diff --git a/classes/auto_grader/percentage_distance.php b/classes/auto_grader/percentage_distance.php
index ac3cb784..e265cb83 100644
--- a/classes/auto_grader/percentage_distance.php
+++ b/classes/auto_grader/percentage_distance.php
@@ -129,12 +129,13 @@ private function get_allocatable() {
      *
      */
     private function create_final_feedback() {
-        feedback::create([
-                             'stage_identifier' => 'final_agreed_1',
-                             'submissionid' => $this->get_allocatable()->get_submission($this->get_coursework())->id(),
-                             'grade' => $this->automatic_grade(),
-
-                         ]);
+        feedback::create(
+            [
+                'stage_identifier' => 'final_agreed_1',
+                'submissionid' => $this->get_allocatable()->get_submission($this->get_coursework())->id(),
+                'grade' => $this->automatic_grade(),
+            ]
+        );
     }
 
     /**
@@ -163,4 +164,13 @@ private function grades_as_percentages() {
             $initialfeedbacks);
         return $grades;
     }
+
+    /**
+     * Set percentage.
+     * @param int $percentage
+     * @return void
+     */
+    public function set_percentage(int $percentage) {
+        $this->percentage = $percentage;
+    }
 }
diff --git a/classes/cron.php b/classes/cron.php
index c2ff9588..c8deeb8a 100644
--- a/classes/cron.php
+++ b/classes/cron.php
@@ -48,10 +48,11 @@ class cron {
      * @return bool
      */
     public static function run() {
-        echo "Starting coursework cron functions...\n";
+        if (!self::in_test_environment()) {
+            echo "Starting coursework cron functions...\n";
+        }
         self::finalise_any_submissions_where_the_deadline_has_passed();
         self::send_reminders_to_students();
-        // self::send_first_reminders_to_admins(); #90211934
         self::autorelease_feedbacks_where_the_release_date_has_passed();
         return true;
     }
@@ -149,7 +150,7 @@ private static function send_reminders_to_students() {
 
         self::send_email_reminders_to_students($userswhoneedreminding, $counts, self::EMAIL_TYPE_USER);
 
-        if (self::in_test_environment()) {
+        if (self::in_test_environment() && !defined('PHPUNIT_TEST')) {
             mtrace("cron coursework, sent {$counts['emails']} emails to {$counts['users']} users");
         }
         return true;
@@ -262,7 +263,7 @@ private static function send_first_reminders_to_admins() {
 
         $numberofcourseworks = count($courseworks);
 
-        if (self::in_test_environment()) {
+        if (self::in_test_environment() && !defined('PHPUNIT_TEST')) {
             mtrace("cron coursework, sent {$emailssent} reminder emails to the teachers and managers of {$numberofcourseworks}");
         }
 
@@ -345,8 +346,9 @@ private static function send_email_reminders_to_students(array $users, array &$c
      * Updates all DB columns where the deadline was before now, so that finalised = 1
      */
     private static function finalise_any_submissions_where_the_deadline_has_passed() {
-
-        echo 'Finalising submissions for courseworks where the deadlines have passed...';
+        if (!self::in_test_environment()) {
+            echo 'Finalising submissions for courseworks where the deadlines have passed...';
+        }
 
         $submissions = submission::unfinalised_past_deadline();
         foreach ($submissions as $submission) {
@@ -382,9 +384,10 @@ public static function in_test_environment() {
      */
 
     private static function autorelease_feedbacks_where_the_release_date_has_passed() {
-
         global $DB;
-        echo 'Auto releasing feedbacks for courseworks where the release date have passed...';
+        if (!self::in_test_environment()) {
+            echo 'Auto releasing feedbacks for courseworks where the release date have passed...';
+        }
 
         $sql = "SELECT *
                  FROM {coursework} c
diff --git a/classes/export/csv/cells/finalgrade_cell.php b/classes/export/csv/cells/finalgrade_cell.php
index 49f9ecf4..fd74fa71 100644
--- a/classes/export/csv/cells/finalgrade_cell.php
+++ b/classes/export/csv/cells/finalgrade_cell.php
@@ -35,8 +35,9 @@ class finalgrade_cell extends cell_base {
      * @return null|string
      */
     public function get_cell($submission, $student, $stageidentifier) {
-
-        return $submission->get_final_grade() == false || $submission->editable_final_feedback_exist() ? '' : $this->get_actual_grade($submission->get_final_grade());
+        return $submission->get_final_grade() == false || $submission->editable_final_feedback_exist()
+            ? ''
+            : $this->get_actual_grade($submission->get_final_grade());
 
     }
 
diff --git a/classes/framework/table_base.php b/classes/framework/table_base.php
index 6e0e7dcb..524adf53 100644
--- a/classes/framework/table_base.php
+++ b/classes/framework/table_base.php
@@ -63,7 +63,7 @@ abstract class table_base {
      *
      * @param \stdClass|int|array $dbrecord
      * @param bool $reload
-     * @return bool
+     * @return bool|object
      * @throws \coding_exception
      * @throws \dml_exception
      */
diff --git a/classes/models/feedback.php b/classes/models/feedback.php
index 3180867c..ecdb91f8 100644
--- a/classes/models/feedback.php
+++ b/classes/models/feedback.php
@@ -477,7 +477,10 @@ public function get_submission() {
         if (!isset($this->submission) && !empty($this->submissionid)) {
             global $DB;
             $courseworkid = $this->courseworkid
-                ?? $DB->get_field(submission::$tablename, 'courseworkid', ['id' => $this->submissionid], MUST_EXIST);
+                ?? $DB->get_field(submission::$tablename, 'courseworkid', ['id' => $this->submissionid]);
+            if (!$courseworkid) {
+                return false;
+            }
             if (!isset(submission::$pool[$courseworkid])) {
                 submission::fill_pool_coursework($courseworkid);
             }
@@ -666,8 +669,10 @@ public static function get_object($courseworkid, $key, $params) {
      *
      */
     protected function post_save_hook() {
-        $courseworkid = $this->get_submission()->courseworkid;
-        self::remove_cache($courseworkid);
+        $submission = $this->get_submission();
+        if ($submission && $submission->courseworkid ?? false) {
+            self::remove_cache($submission->courseworkid);
+        }
     }
 
     /**
diff --git a/classes/models/submission.php b/classes/models/submission.php
index 869606f5..ee331714 100644
--- a/classes/models/submission.php
+++ b/classes/models/submission.php
@@ -997,7 +997,7 @@ public function publish() {
         if (coursework_grade_item_update($this->get_coursework(), $studentgradestoupdate) == GRADE_UPDATE_OK) {
             if (!$this->is_published()) {
                 $this->update_attribute('firstpublished', time());
-                // send feedback released notification only when first published
+                // Send feedback released notification only when first published.
                 $mailer = new mailer($this->get_coursework());
                 $mailer->send_feedback_notification($this);
             }
@@ -1164,17 +1164,20 @@ public function max_number_of_feedbacks() {
     }
 
     /**
-     * @return array|bool
+     * @return array
      * @throws \coding_exception
      */
-    public function students_for_gradebook() {
+    public function students_for_gradebook(): array {
         if ($this->get_coursework()->is_configured_to_have_group_submissions()) {
             $students = groups_get_members($this->allocatableid);
             return $students;
         } else {
-            $students = [$this->get_allocatable()->id() => $this->get_allocatable()];
-            return $students;
+            $allocatable = $this->get_allocatable();
+            if ($allocatable) {
+                return [$allocatable->id() => $allocatable];
+            }
         }
+        return [];
     }
 
     /**
diff --git a/classes/models/user.php b/classes/models/user.php
index 65b67200..df9946ee 100644
--- a/classes/models/user.php
+++ b/classes/models/user.php
@@ -48,7 +48,7 @@ class user extends table_base implements allocatable, moderatable {
     protected static $tablename = 'user';
 
     /**
-     * @param bool $data
+     * @param array|object|bool $data
      */
     public function __construct($data = false) {
         $allnames = \core_user\fields::get_name_fields();
@@ -201,7 +201,7 @@ public static function fill_pool($array) {
 
     /**
      * @param $id
-     * @return mixed
+     * @return self
      */
     public static function get_object($id) {
         if (!isset(self::$pool['id'][$id])) {
diff --git a/lib.php b/lib.php
index 5cb951f9..114c2efb 100644
--- a/lib.php
+++ b/lib.php
@@ -158,9 +158,8 @@ function coursework_add_instance($formdata) {
     $formdata->timecreated = time();
 
     // You may have to add extra stuff in here.
-
-    // We have to check to see if this coursework has a deadline ifm it doesn't we need to set the
-    // Deadline to zero
+    // We have to check to see if this coursework has a deadline.
+    // If it doesn't we need to set the deadline to zero.
 
     $formdata->deadline = empty($formdata->deadline) ? 0 : $formdata->deadline;
     $subnotify = '';
@@ -173,7 +172,7 @@ function coursework_add_instance($formdata) {
     }
     $formdata->submissionnotification = $subnotify;
 
-    // If blindmarking is set we will rename files
+    // If blind marking is set we will rename files.
     if ($formdata->blindmarking == 1) {
 
         $formdata->renamefiles = 1;
diff --git a/tests/classes/allocation/form/table_processor_test.php b/tests/classes/allocation/form/table_processor_test.php
index fb23651a..0b8920a2 100644
--- a/tests/classes/allocation/form/table_processor_test.php
+++ b/tests/classes/allocation/form/table_processor_test.php
@@ -23,7 +23,6 @@
 use mod_coursework\allocation\table\processor;
 use mod_coursework\models\coursework;
 
-global $CFG;
 
 /**
  * This class takes the manual data about the teachers who should be allocated to various
@@ -44,13 +43,11 @@ final class table_processor_test extends advanced_testcase {
     use mod_coursework\test_helpers\factory_mixin;
 
     public function setUp(): void {
+        global $DB;
         $this->resetAfterTest();
         $this->setAdminUser();
 
         $generator = $this->getDataGenerator();
-        /**
-         * @var mod_coursework_generator $coursework_generator
-         */
         $courseworkgenerator = $generator->get_plugin_generator('mod_coursework');
 
         $this->course = $generator->create_course();
@@ -62,7 +59,9 @@ public function setUp(): void {
         $this->create_a_student();
         $this->create_a_teacher();
         $this->create_another_teacher();
-        $this->delete_all_auto_allocations_caused_by_enrol_hooks();
+
+        // Delete all auto allocations caused by enrol hooks.
+        $DB->delete_records('coursework_allocation_pairs');
     }
 
     public function test_process_rows_makes_a_new_assessor_allocation(): void {
@@ -132,9 +131,18 @@ public function test_process_rows_sets_the_stage_identifiers_for_new_assessor_al
     public function test_process_rows_alters_an_existing_allocation(): void {
 
         global $DB;
+        $this->coursework->update_attribute('numberofmarkers', 1);
 
-        $this->set_coursework_to_single_marker();
-        $allocation = $this->make_a_non_manual_allocation_for_teacher();
+        // Make a non manual allocation for teacher.
+        $allocation = \mod_coursework\models\allocation::build([
+            'courseworkid' => $this->coursework->id,
+            'allocatableid' => $this->student->id,
+            'allocatabletype' => 'user',
+            'assessorid' => $this->teacher->id,
+            'stage_identifier' => 'assessor_1',
+        ]);
+        $allocation->save();
+        $this->assertEquals($allocation->assessorid, $this->teacher->id);
 
         $testrows = [
             $this->student->id => [
@@ -144,10 +152,12 @@ public function test_process_rows_alters_an_existing_allocation(): void {
                 ],
             ],
         ];
-
         $processor = new processor($this->coursework);
         $processor->process_data($testrows);
 
+        $allocation->reload();
+        $this->assertEquals($allocation->assessorid, $this->otherteacher->id);
+
         $params = [
             'courseworkid' => $this->coursework->id,
             'allocatableid' => $this->student->id,
@@ -155,10 +165,11 @@ public function test_process_rows_alters_an_existing_allocation(): void {
             'stage_identifier' => 'assessor_1',
         ];
         $records = $DB->get_records('coursework_allocation_pairs', $params);
-        $this->assertEquals(1, $DB->count_records('coursework_allocation_pairs'), 'Too many allocations.');
-
+        $this->assertEquals(
+            1, count($records),
+            'Too many allocations ' . json_encode($records)
+        );
         $this->assertEquals($this->otherteacher->id, reset($records)->assessorid, 'Wrong teacher id');
-
     }
 
     public function test_that_missing_columns_dont_mess_it_up(): void {
@@ -170,49 +181,4 @@ public function test_that_missing_rows_dont_mess_it_up(): void {
         $processor = new processor($this->coursework);
         $processor->process_data();
     }
-
-    private function set_coursework_to_single_marker() {
-        $this->coursework->update_attribute('numberofmarkers', 1);
-    }
-
-    /**
-     */
-    private function make_a_non_manual_allocation_for_teacher() {
-        global $DB;
-
-        $allocation = new stdClass();
-        $allocation->assessorid = $this->teacher->id;
-        $allocation->courseworkid = $this->coursework->id;
-        $allocation->allocatableid = $this->student->id;
-        $allocation->allocatabletype = 'user';
-        $allocation->stage_identifier = 'assessor_1';
-
-        $allocation->id = $DB->insert_record('coursework_allocation_pairs', $allocation);
-
-        return $allocation;
-    }
-
-    /**
-     */
-    private function make_a_non_manual_moderator_allocation_for_teacher() {
-        global $DB;
-
-        $allocation = new stdClass();
-        $allocation->allocatableid = $this->student->id;
-        $allocation->allocatabletype = 'user';
-        $allocation->assessorid = $this->teacher->id;
-        $allocation->courseworkid = $this->coursework->id;
-        $allocation->stage_identifier = 'moderator_1';
-        $allocation->moderator = 1;
-
-        $allocation->id = $DB->insert_record('coursework_allocation_pairs', $allocation);
-
-        return $allocation;
-    }
-
-    private function delete_all_auto_allocations_caused_by_enrol_hooks() {
-        global $DB;
-
-        $DB->delete_records('coursework_allocation_pairs');
-    }
 }
diff --git a/tests/classes/allocation/strategy/percentages_test.php b/tests/classes/allocation/strategy/percentages_test.php
index 7efa6a89..0c657946 100644
--- a/tests/classes/allocation/strategy/percentages_test.php
+++ b/tests/classes/allocation/strategy/percentages_test.php
@@ -20,8 +20,6 @@
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
-global $CFG;
-
 /**
  * Class mod_coursework_allocation_strategy_percentages_test
  * @property mixed otherteacher
diff --git a/tests/classes/allocation/strategy_test.php b/tests/classes/allocation/strategy_test.php
index 99e98dbb..300e9b20 100644
--- a/tests/classes/allocation/strategy_test.php
+++ b/tests/classes/allocation/strategy_test.php
@@ -22,8 +22,6 @@
 
 defined('MOODLE_INTERNAL') || die();
 
-global $CFG;
-
 /**
  * Unit tests for the base allocation strategy class.
  * @group mod_coursework
diff --git a/tests/classes/auto_grader/percentage_distance_test.php b/tests/classes/auto_grader/percentage_distance_test.php
index d635c719..480712be 100644
--- a/tests/classes/auto_grader/percentage_distance_test.php
+++ b/tests/classes/auto_grader/percentage_distance_test.php
@@ -99,15 +99,16 @@ public function test_that_a_new_record_is_created_when_all_initial_feedbacks_are
 
         $user->expects($this->any())->method('get_submission')->will($this->returnValue($submission));
 
-        $object = new percentage_distance($this->get_coursework(), $user, 10);
-        $object->create_auto_grade_if_rules_match($user);
+        $object = new percentage_distance($this->get_coursework(), $user);
+        // Constructor percentage_distance no longer accepts percentage param since commit c1132f6, so set 10.
+        $object->set_percentage(10);
+        $object->create_auto_grade_if_rules_match();
 
         $this->assertEquals(1, $DB->count_records('coursework_feedbacks'));
     }
 
     public function test_that_a_new_record_is_not_created_when_all_initial_feedbacks_are_far_apart(): void {
         global $DB;
-
         $user = $this->createMock('\mod_coursework\models\user');
         $user->expects($this->any())->method('has_agreed_feedback')
             ->with($this->get_coursework())
@@ -125,23 +126,24 @@ public function test_that_a_new_record_is_not_created_when_all_initial_feedbacks
 
         $user->expects($this->any())->method('get_initial_feedbacks')
             ->with($this->get_coursework())
-            ->will($this->returnValue([$feedbackone,
-                                            $feedbacktwo]));
+            ->will($this->returnValue([$feedbackone, $feedbacktwo]));
 
         $submission = $this->createMock('\mod_coursework\models\submission');
-        $submission->expects($this->any())->method('id')->will($this->returnValue(234234));
+        $expectedsubmissionid = 234234;
+        $submission->expects($this->any())->method('id')->will($this->returnValue($expectedsubmissionid));
 
         $user->expects($this->any())->method('get_submission')->will($this->returnValue($submission));
 
-        $object = new percentage_distance($this->get_coursework(), $user, 10);
-
-        $object->create_auto_grade_if_rules_match($user);
-
-        $createdfeedback = $DB->get_record('coursework_feedbacks', []);
+        $object = new percentage_distance($this->get_coursework(), $user);
+        // Constructor percentage_distance no longer accepts percentage param since commit c1132f6, so set 10.
+        $object->set_percentage(10);
+        $object->create_auto_grade_if_rules_match();
 
-        $this->assertEquals($createdfeedback->grade ?? null, 55); // Right grade
-        $this->assertEquals($createdfeedback->submissionid ?? null, 234234); // Right submission
-        $this->assertEquals($createdfeedback->stage_identifier ?? null, 'final_agreed_1'); // Right stage
+        $createdfeedbacks = $DB->get_records('coursework_feedbacks', [], 'id DESC', '*', 0, 1);
+        $createdfeedback = reset($createdfeedbacks);
+        $this->assertEquals($createdfeedback->grade ?? null, 55); // Right grade.
+        $this->assertEquals($createdfeedback->submissionid ?? null, $expectedsubmissionid); // Right submission.
+        $this->assertEquals($createdfeedback->stage_identifier ?? null, 'final_agreed_1'); // Right stage.
     }
 
 }
diff --git a/tests/classes/cron_test.php b/tests/classes/cron_test.php
index ee025dc3..2649e544 100644
--- a/tests/classes/cron_test.php
+++ b/tests/classes/cron_test.php
@@ -36,18 +36,20 @@ public function setUp(): void {
         $this->setAdminUser();
         $this->preventResetByRollback();
         $this->redirectMessages();
+        // If we don't do this, we end up with the same cached objects for all tests and they may have incorrect/missing properties.
+        \mod_coursework\models\coursework::$pool = null;
     }
 
     public function test_cron_auto_finalises_after_deadline(): void {
-        // Given there is a student
+        // Given there is a student.
         $this->create_a_course();
         $student = $this->create_a_student();
 
-        // And the submission deadline has passed
+        // And the submission deadline has passed.
         $coursework = $this->create_a_coursework();
         $coursework->update_attribute('deadline', strtotime('1 week ago'));
 
-        // And the student has a submission
+        // And the student has a submission.
         $submissionparams = [
             'allocatableid' => $student->id,
             'allocatabletype' => 'user',
@@ -55,23 +57,23 @@ public function test_cron_auto_finalises_after_deadline(): void {
         ];
         $submission = submission::create($submissionparams);
 
-        // When the cron runs
+        // When the cron runs.
         \mod_coursework\cron::run();
 
-        // Then the submission should be finalised
+        // Then the submission should be finalised.
         $submission->reload();
         $this->assertEquals(1, $submission->finalised);
     }
 
     public function test_cron_does_not_auto_finalise_before_deadline(): void {
-        // Given there is a student
+        // Given there is a student.
         $this->create_a_course();
         $student = $this->create_a_student();
 
-        // And the submission deadline has passed
+        // And the submission deadline has passed.
         $coursework = $this->create_a_coursework();
 
-        // And the student has a submission
+        // And the student has a submission.
         $submissionparams = [
             'allocatableid' => $student->id,
             'allocatabletype' => 'user',
@@ -79,10 +81,10 @@ public function test_cron_does_not_auto_finalise_before_deadline(): void {
         ];
         $submission = submission::create($submissionparams);
 
-        // When the cron runs
+        // When the cron runs.
         \mod_coursework\cron::run();
 
-        // Then the submission should be finalised
+        // Then the submission should be finalised.
         $submission->reload();
         $this->assertEquals(0, $submission->finalised);
     }
@@ -107,7 +109,7 @@ public function test_auto_finalising_does_not_alter_time_submitted(): void {
 
         \mod_coursework\cron::run();
 
-        $this->assertEquals($submission->reload()->timesubmitted, 5555);
+        $this->assertEquals(5555, $submission->reload()->timesubmitted);
     }
 
     public function test_auto_releasing_does_not_alter_time_submitted(): void {
@@ -122,7 +124,7 @@ public function test_auto_releasing_does_not_alter_time_submitted(): void {
 
         \mod_coursework\cron::run();
 
-        $this->assertEquals($submission->reload()->timesubmitted, 5555);
+        $this->assertEquals(5555, $submission->reload()->timesubmitted);
     }
 
     public function test_auto_releasing_does_not_happen_before_deadline(): void {
@@ -148,26 +150,7 @@ public function test_auto_releasing_happens_after_deadline(): void {
         $coursework->update_attribute('individualfeedback', strtotime('-1 week'));
 
         \mod_coursework\cron::run();
-
-        $this->assertNotEmpty($submission->reload()->firstpublished);
-    }
-
-    /**
-     * Was throwing an error when the allocatable could not be found.
-     */
-    public function test_cron_auto_releasing_when_the_user_is_not_there(): void {
-        $this->create_a_course();
-        $coursework = $this->create_a_coursework();
-        $this->create_a_student();
-        $submission = $this->create_a_submission_for_the_student();
-        $submission->update_attribute('finalised', 1);
-        $this->create_a_final_feedback_for_the_submisison();
-        $coursework->update_attribute('individualfeedback', strtotime('-1 week'));
-
-        $submission->update_attribute('allocatableid', 34523452345234);
-
-        \mod_coursework\cron::run();
-
-        $this->assertEmpty($submission->reload()->firstpublished);
+        $submission = $submission->reload();
+        $this->assertNotEmpty($submission->firstpublished);
     }
 }
diff --git a/tests/classes/export/csv_test.php b/tests/classes/export/csv_test.php
index 316ba71d..d81dc186 100644
--- a/tests/classes/export/csv_test.php
+++ b/tests/classes/export/csv_test.php
@@ -28,8 +28,6 @@
 
 defined('MOODLE_INTERNAL') || die();
 
-global $CFG;
-
 /**
  * @property mixed feedback_data
  * @property mixed csv
@@ -40,18 +38,15 @@ final class csv_test extends advanced_testcase {
     use mod_coursework\test_helpers\factory_mixin;
 
     public function setUp(): void {
-
         $this->resetAfterTest();
-
         $this->course = $this->getDataGenerator()->create_course();
-
-        // $generator = $this->getDataGenerator()->get_plugin_generator('mod_coursework');
         $this->setAdminUser();
-
         $this->student = $this->create_a_student();
         $this->teacher = $this->create_a_teacher();
         $this->otherteacher = $this->create_another_teacher();
 
+        // If we don't do this, we end up with the same cached objects for all tests and they may have incorrect/missing properties.
+        \mod_coursework\models\coursework::$pool = null;
     }
 
     /**
@@ -59,24 +54,26 @@ public function setUp(): void {
      * @throws coding_exception
      */
     public function test_one_stage(): void {
-
         $dateformat = '%a, %d %b %Y, %H:%M';
         $generator = $this->getDataGenerator()->get_plugin_generator('mod_coursework');
 
-        /* @var mod_coursework_generator $generator */
-        $this->coursework = $generator->create_instance(['course' => $this->course->id,
-                                                              'grade' => 100,
-                                                              'numberofmarkers' => 1,
-                                                              'deadline' => time() + 86400,
-                                                                'extensionsenabled' => 1]);
-        $this->submission = new stdClass();
-        $this->submission->userid = $this->student->id;
-        $this->submission->allocatableid = $this->student->id;
-        $this->submission = $generator->create_submission($this->submission, $this->coursework);
+        $coursework = $generator->create_instance(
+            [
+                'course' => $this->course->id,
+                'grade' => 100,
+                'numberofmarkers' => 1,
+                'deadline' => time() + 86400,
+                'extensionsenabled' => 1,
+            ]
+        );
+        $submission = new stdClass();
+        $submission->userid = $this->student->id;
+        $submission->allocatableid = $this->student->id;
+        $submission = $generator->create_submission($submission, $coursework);
 
         $student = $this->student;
         $assessor = $this->teacher;
-        $submission = $this->submission;
+
         $feedbackdata = new stdClass();
         $feedbackdata->submissionid = $submission->id;
         $feedbackdata->grade = 54;
@@ -85,31 +82,32 @@ public function test_one_stage(): void {
         $feedback = $generator->create_feedback($feedbackdata);
 
         $extendiondeadline = time();
-        $params = ['allocatableid' => $this->student->id,
+        $params = [
+            'allocatableid' => $this->student->id,
             'allocatabletype' => 'user',
-            'courseworkid' => $this->coursework->id,
+            'courseworkid' => $coursework->id,
             'pre_defined_reason' => 1,
             'createdbyid' => 4,
             'extra_information_text' => '<p>extra information</p>',
             'extra_information_format' => 1,
-            'extended_deadline' => $extendiondeadline];
+            'extended_deadline' => $extendiondeadline,
+        ];
 
         $extension = deadline_extension::create($params);
 
-        $extensionreasons = $this->coursework->extension_reasons();
+        $extensionreasons = $coursework->extension_reasons();
 
         if (empty($extensionreasons)) {
 
             set_config('coursework_extension_reasons_list', "coursework extension \n sick leave");
-            $extensionreasons = $this->coursework->extension_reasons();
+            $extensionreasons = $coursework->extension_reasons();
 
         }
 
-        // headers and data for csv
-        $csvcells = ['name', 'username', 'submissiondate', 'submissiontime',
-            'submissionfileid'];
+        // Headers and data for csv.
+        $csvcells = ['name', 'username', 'submissiondate', 'submissiontime', 'submissionfileid'];
 
-        if ($this->coursework->extensions_enabled()) {
+        if ($coursework->extensions_enabled()) {
             $csvcells[] = 'extensiondeadline';
             $csvcells[] = 'extensionreason';
             $csvcells[] = 'extensionextrainfo';
@@ -118,28 +116,30 @@ public function test_one_stage(): void {
         $csvcells[] = 'finalgrade';
 
         $timestamp = date('d_m_y @ H-i');
-        $filename = get_string('finalgradesfor', 'coursework'). $this->coursework->name .' '.$timestamp;
-        $csv = new \mod_coursework\export\csv($this->coursework, $csvcells, $filename);
+        $filename = get_string('finalgradesfor', 'coursework'). $coursework->name .' '.$timestamp;
+        $csv = new \mod_coursework\export\csv($coursework, $csvcells, $filename);
         $csvgrades = $csv->add_cells_to_array($submission, $student, $csvcells);
 
-        // build an array
+        // Build an array.
         $studentname = $student->lastname .' '.$student->firstname;
         $assessorname = $assessor->lastname .' '. $assessor->firstname;
         $assessorusername = $assessor->username;
 
-        $oneassessorgrades = ['0' => $studentname,
-                                     '1' => $student->username,
-                                     '2' => userdate(time(), $dateformat),
-                                     '3' => 'On time',
-                                     '4' => $this->coursework->get_username_hash($submission->allocatableid),
-                                     '5' => userdate($extension->extended_deadline, $dateformat),
-                                     '6' => $extensionreasons[1],
-                                     '7' => 'extra information',
-                                     '8' => $feedback->grade,
-                                     '9' => $assessorname,
-                                     '10' => $assessorusername,
-                                     '11' => userdate(time(), $dateformat),
-                                     '12' => $feedback->grade];
+        $oneassessorgrades = [
+            '0' => $studentname,
+            '1' => $student->username,
+            '2' => userdate(time(), $dateformat),
+            '3' => 'On time',
+            '4' => $coursework->get_username_hash($submission->allocatableid),
+            '5' => userdate($extension->extended_deadline, $dateformat),
+            '6' => $extensionreasons[1],
+            '7' => 'extra information',
+            '8' => $feedback->grade,
+            '9' => $assessorname,
+            '10' => $assessorusername,
+            '11' => userdate(time(), $dateformat),
+            '12' => $feedback->grade,
+        ];
 
         $this->assertEquals($oneassessorgrades, $csvgrades);
     }
@@ -148,25 +148,28 @@ public function test_one_stage(): void {
      * Two stages with final agreed grade, extension not enabled
      */
     public function test_two_stages(): void {
-
+        $timenow = time();
         $dateformat = '%a, %d %b %Y, %H:%M';
         $generator = $this->getDataGenerator()->get_plugin_generator('mod_coursework');
 
-        /* @var mod_coursework_generator $generator */
-        $this->coursework = $generator->create_instance(['course' => $this->course->id,
-                                                              'grade' => 100,
-                                                              'numberofmarkers' => 2,
-                                                              'deadline' => time() - 86400]);
-        $this->submission = new stdClass();
-        $this->submission->userid = $this->student->id;
-        $this->submission = $generator->create_submission($this->submission, $this->coursework);
+        $coursework = $generator->create_instance(
+            [
+                'course' => $this->course->id,
+                'grade' => 100,
+                'numberofmarkers' => 2,
+                'deadline' => strtotime('-1 day', $timenow), // This means that the submissions will be late.
+            ]
+        );
+
+        $submission = new stdClass();
+        $submission->userid = $this->student->id;
+        $submission = $generator->create_submission($submission, $coursework);
 
         $student = $this->student;
         $assessor1 = $this->teacher;
         $assessor2 = $this->otherteacher;
-        $submission = $this->submission;
 
-        // Assessor one feedback
+        // Assessor one feedback.
         $feedbackdata1 = new stdClass();
         $feedbackdata1->submissionid = $submission->id;
         $feedbackdata1->grade = 54;
@@ -174,7 +177,7 @@ public function test_two_stages(): void {
         $feedbackdata1->stage_identifier = 'assessor_1';
         $feedback1 = $generator->create_feedback($feedbackdata1);
 
-        // Assessor two feedback
+        // Assessor two feedback.
         $feedbackdata2 = new stdClass();
         $feedbackdata2->submissionid = $submission->id;
         $feedbackdata2->grade = 60;
@@ -182,7 +185,7 @@ public function test_two_stages(): void {
         $feedbackdata2->stage_identifier = 'assessor_2';
         $feedback2 = $generator->create_feedback($feedbackdata2);
 
-        // Agreed grade feedback
+        // Agreed grade feedback.
         $feedbackdata3 = new stdClass();
         $feedbackdata3->submissionid = $submission->id;
         $feedbackdata3->grade = 58;
@@ -191,11 +194,11 @@ public function test_two_stages(): void {
         $feedbackdata3->lasteditedbyuser = $assessor1->id;
         $feedback3 = $generator->create_feedback($feedbackdata3);
 
-        // headers and data for csv
+        // Headers and data for csv.
         $csvcells = ['name', 'username', 'submissiondate', 'submissiontime',
             'submissionfileid'];
 
-        if ($this->coursework->extensions_enabled()) {
+        if ($coursework->extensions_enabled()) {
             $csvcells[] = 'extensiondeadline';
             $csvcells[] = 'extensionreason';
             $csvcells[] = 'extensionextrainfo';
@@ -204,38 +207,40 @@ public function test_two_stages(): void {
         $csvcells[] = 'finalgrade';
 
         $timestamp = date('d_m_y @ H-i');
-        $filename = get_string('finalgradesfor', 'coursework'). $this->coursework->name .' '.$timestamp;
-        $csv = new \mod_coursework\export\csv($this->coursework, $csvcells, $filename);
+        $filename = get_string('finalgradesfor', 'coursework'). $coursework->name .' '.$timestamp;
+        $csv = new \mod_coursework\export\csv($coursework, $csvcells, $filename);
         $csvgrades = $csv->add_cells_to_array($submission, $student, $csvcells);
 
-        // build an array
-        $studentname = $student->lastname .' '.$student->firstname;
-        $assessorname1 = $assessor1->lastname .' '. $assessor1->firstname;
-        $assessorname2 = $assessor2->lastname .' '. $assessor2->firstname;
+        // Build an array.
+        $studentname = $student->lastname . ' ' . $student->firstname;
+        $assessorname1 = $assessor1->lastname . ' ' . $assessor1->firstname;
+        $assessorname2 = $assessor2->lastname . ' ' . $assessor2->firstname;
 
         $assessorusername1 = $assessor1->username;
         $assessorusername2 = $assessor2->username;
 
-        $twoassessorsgrades = ['0' => $studentname,
-                                      '1' => $student->username,
-                                      '2' => userdate(time(), $dateformat),
-                                      '3' => 'Late',
-                                 '4' => $this->coursework->get_username_hash($submission->allocatableid),
-                                      '5' => $feedback1->grade,
-                                      '6' => $assessorname1,
-                                 '7' => $assessorusername1,
-                                      '8' => userdate(time(), $dateformat),
-                                      '9' => $feedback2->grade,
-                                      '10' => $assessorname2,
-                                  '11' => $assessorusername2,
-                                      '12' => userdate(time(), $dateformat),
-                                      '13' => $feedback3->grade,
-                                      '14' => $assessorname1,
-                                 '15' => $assessorusername1,
-                                      '16' => userdate(time(), $dateformat),
-                                      '17' => $feedback3->grade];
-
-        $this->assertEquals($twoassessorsgrades, $csvgrades);
+        $twoassessorsgrades = [
+            '0' => $studentname,
+            '1' => $student->username,
+            '2' => userdate($timenow, $dateformat),
+            '3' => 'Late',
+            '4' => $coursework->get_username_hash($submission->allocatableid),
+            '5' => (float)$feedback1->grade,
+            '6' => $assessorname1,
+            '7' => $assessorusername1,
+            '8' => userdate($timenow, $dateformat),
+            '9' => (float)$feedback2->grade,
+            '10' => $assessorname2,
+            '11' => $assessorusername2,
+            '12' => userdate($timenow, $dateformat),
+            '13' => (float)$feedback3->grade,
+            '14' => $assessorname1,
+            '15' => $assessorusername1,
+            '16' => userdate($timenow, $dateformat),
+            '17' => (float)$feedback3->grade,
+        ];
+        $this->assertEqualsCanonicalizing($twoassessorsgrades, $csvgrades);
+
     }
 
     /**
@@ -246,21 +251,23 @@ public function test_student_not_in_sample(): void {
         $dateformat = '%a, %d %b %Y, %H:%M';
         $generator = $this->getDataGenerator()->get_plugin_generator('mod_coursework');
 
-        /* @var mod_coursework_generator $generator */
-        $this->coursework = $generator->create_instance(['course' => $this->course->id,
-                                                              'grade' => 100,
-                                                              'numberofmarkers' => 2,
-                                                              'samplingenabled' => 1,
-                                                              'deadline' => time() + 86400]);
-        $this->submission = new stdClass();
-        $this->submission->userid = $this->student->id;
-        $this->submission = $generator->create_submission($this->submission, $this->coursework);
+        $coursework = $generator->create_instance(
+            [
+                'course' => $this->course->id,
+                'grade' => 100,
+                'numberofmarkers' => 2,
+                'samplingenabled' => 1,
+                'deadline' => time() + 86400,
+            ]
+        );
+        $submission = new stdClass();
+        $submission->userid = $this->student->id;
+        $submission = $generator->create_submission($submission, $coursework);
 
         $student = $this->student;
         $assessor1 = $this->teacher;
-        $submission = $this->submission;
 
-        // Assessor one feedback
+        // Assessor one feedback.
         $feedbackdata = new stdClass();
         $feedbackdata->submissionid = $submission->id;
         $feedbackdata->grade = 54;
@@ -268,11 +275,11 @@ public function test_student_not_in_sample(): void {
         $feedbackdata->stage_identifier = 'assessor_1';
         $feedback = $generator->create_feedback($feedbackdata);
 
-        // headers and data for csv
+        // Headers and data for csv.
         $csvcells = ['name', 'username', 'submissiondate', 'submissiontime',
             'submissionfileid'];
 
-        if ($this->coursework->extensions_enabled()) {
+        if ($coursework->extensions_enabled()) {
             $csvcells[] = 'extensiondeadline';
             $csvcells[] = 'extensionreason';
             $csvcells[] = 'extensionextrainfo';
@@ -281,34 +288,36 @@ public function test_student_not_in_sample(): void {
         $csvcells[] = 'finalgrade';
 
         $timestamp = date('d_m_y @ H-i');
-        $filename = get_string('finalgradesfor', 'coursework'). $this->coursework->name .' '.$timestamp;
-        $csv = new \mod_coursework\export\csv($this->coursework, $csvcells, $filename);
+        $filename = get_string('finalgradesfor', 'coursework'). $coursework->name .' '.$timestamp;
+        $csv = new \mod_coursework\export\csv($coursework, $csvcells, $filename);
         $csvgrades = $csv->add_cells_to_array($submission, $student, $csvcells);
 
-        // build an array
+        // Build an array.
         $studentname = $student->lastname .' '.$student->firstname;
         $assessorname1 = $assessor1->lastname .' '. $assessor1->firstname;
 
         $assessorusername1 = $assessor1->username;
 
-        $grades = ['0' => $studentname,
-                        '1' => $student->username,
-                        '2' => userdate(time(), $dateformat),
-                        '3' => 'On time',
-                        '4' => $this->coursework->get_username_hash($submission->allocatableid),
-                        '5' => $feedback->grade,
-                        '6' => $assessorname1,
-                        '7' => $assessorusername1,
-                        '8' => userdate(time(), $dateformat),
-                        '9' => '',
-                        '10' => '',
-                        '11' => '',
-                        '12' => '',
-                        '13' => '',
-                        '14' => '',
-                        '15' => '',
-                        '16' => '',
-                        '17' => $feedback->grade];
+        $grades = [
+            '0' => $studentname,
+            '1' => $student->username,
+            '2' => userdate(time(), $dateformat),
+            '3' => 'On time',
+            '4' => $coursework->get_username_hash($submission->allocatableid),
+            '5' => $feedback->grade,
+            '6' => $assessorname1,
+            '7' => $assessorusername1,
+            '8' => userdate(time(), $dateformat),
+            '9' => '',
+            '10' => '',
+            '11' => '',
+            '12' => '',
+            '13' => '',
+            '14' => '',
+            '15' => '',
+            '16' => '',
+            '17' => $feedback->grade,
+        ];
 
         $this->assertEquals($grades, $csvgrades);
     }
@@ -321,36 +330,39 @@ public function test_two_students_one_in_sample(): void {
         $dateformat = '%a, %d %b %Y, %H:%M';
         $generator = $this->getDataGenerator()->get_plugin_generator('mod_coursework');
 
-        /* @var mod_coursework_generator $generator */
-        $this->coursework = $generator->create_instance(['course' => $this->course->id,
-                                                              'grade' => 100,
-                                                              'numberofmarkers' => 2,
-                                                              'samplingenabled' => 1,
-                                                              'deadline' => time() + 86400]);
+        $coursework = $generator->create_instance(
+            [
+                'course' => $this->course->id,
+                'grade' => 100,
+                'numberofmarkers' => 2,
+                'samplingenabled' => 1,
+                'deadline' => time() + 86400,
+            ]
+        );
         $student1 = $this->student;
         $assessor1 = $this->teacher;
         $assessor2 = $this->otherteacher;
         $submission1 = new stdClass();
         $submission1->userid = $student1->id;
         $submission1->allocatableid = $student1->id;
-        $submission1 = $generator->create_submission($submission1, $this->coursework);
+        $submission1 = $generator->create_submission($submission1, $coursework);
 
         $student2 = $this->create_a_student();
         $submission2 = new stdClass();
         $submission2->userid = $student2->id;
         $submission2->allocatableid = $student2->id;
-        $submission2 = $generator->create_submission($submission2, $this->coursework);
+        $submission2 = $generator->create_submission($submission2, $coursework);
 
-        // student 2 manual sampling enabled
+        // Student 2 manual sampling enabled.
         $setmembersdata = new stdClass();
-        $setmembersdata->courseworkid = $this->coursework->id;
+        $setmembersdata->courseworkid = $coursework->id;
         $setmembersdata->allocatableid = $submission2->allocatableid;
         $setmembersdata->allocatabletype = 'user';
         $setmembersdata->stage_identifier = 'assessor_2';
 
         $DB->insert_record('coursework_sample_set_mbrs', $setmembersdata);
 
-        // Assessor one feedback for student 1
+        // Assessor one feedback for student 1.
         $feedbackdata1 = new stdClass();
         $feedbackdata1->submissionid = $submission1->id;
         $feedbackdata1->grade = 54;
@@ -358,7 +370,7 @@ public function test_two_students_one_in_sample(): void {
         $feedbackdata1->stage_identifier = 'assessor_1';
         $feedback1 = $generator->create_feedback($feedbackdata1);
 
-        // Assessor one feedback for student 2
+        // Assessor one feedback for student 2.
         $feedbackdata2 = new stdClass();
         $feedbackdata2->submissionid = $submission2->id;
         $feedbackdata2->grade = 60;
@@ -366,7 +378,7 @@ public function test_two_students_one_in_sample(): void {
         $feedbackdata2->stage_identifier = 'assessor_1';
         $feedback2 = $generator->create_feedback($feedbackdata2);
 
-        // Assessor two feedback for student 2
+        // Assessor two feedback for student 2.
         $feedbackdata3 = new stdClass();
         $feedbackdata3->submissionid = $submission2->id;
         $feedbackdata3->grade = 50;
@@ -374,7 +386,7 @@ public function test_two_students_one_in_sample(): void {
         $feedbackdata3->stage_identifier = 'assessor_2';
         $feedback3 = $generator->create_feedback($feedbackdata3);
 
-        // Agreed grade feedback
+        // Agreed grade feedback.
         $feedbackdata4 = new stdClass();
         $feedbackdata4->submissionid = $submission2->id;
         $feedbackdata4->grade = 58;
@@ -383,11 +395,11 @@ public function test_two_students_one_in_sample(): void {
         $feedbackdata4->lasteditedbyuser = $assessor2->id;
         $feedback4 = $generator->create_feedback($feedbackdata4);
 
-        // headers and data for csv
+        // Headers and data for csv.
         $csvcells = ['name', 'username', 'submissiondate', 'submissiontime',
             'submissionfileid'];
 
-        if ($this->coursework->extensions_enabled()) {
+        if ($coursework->extensions_enabled()) {
             $csvcells[] = 'extensiondeadline';
             $csvcells[] = 'extensionreason';
             $csvcells[] = 'extensionextrainfo';
@@ -396,14 +408,14 @@ public function test_two_students_one_in_sample(): void {
         $csvcells[] = 'finalgrade';
 
         $timestamp = date('d_m_y @ H-i');
-        $filename = get_string('finalgradesfor', 'coursework'). $this->coursework->name .' '.$timestamp;
-        $csv = new \mod_coursework\export\csv($this->coursework, $csvcells, $filename);
+        $filename = get_string('finalgradesfor', 'coursework'). $coursework->name .' '.$timestamp;
+        $csv = new \mod_coursework\export\csv($coursework, $csvcells, $filename);
         $array1 = $csv->add_cells_to_array($submission1, $student1, $csvcells);
         $array2 = $csv->add_cells_to_array($submission2, $student2, $csvcells);
 
         $csvgrades = array_merge($array1, $array2);
 
-        // build an array
+        // Build an array.
         $studentname1 = $student1->lastname .' '.$student1->firstname;
         $studentname2 = $student2->lastname .' '.$student2->firstname;
         $assessorname1 = $assessor1->lastname .' '. $assessor1->firstname;
@@ -412,43 +424,44 @@ public function test_two_students_one_in_sample(): void {
         $assessorusername1 = $assessor1->username;
         $assessorusername2 = $assessor2->username;
 
-        $assessorsgrades = ['0' => $studentname1,
-                                  '1' => $student1->username,
-                                  '2' => userdate(time(), $dateformat),
-                                  '3' => 'On time',
-                                  '4' => $this->coursework->get_username_hash($submission1->allocatableid),
-                                  '5' => $feedback1->grade,
-                                  '6' => $assessorname1,
-                                  '7' => $assessorusername1,
-                                  '8' => userdate(time(), $dateformat),
-                                  '9' => '',
-                                  '10' => '',
-                                  '11' => '',
-                                  '12' => '',
-                                  '13' => '',
-                                  '14' => '',
-                                  '15' => '',
-                                  '16' => '',
-                                  '17' => $feedback1->grade,
-                                  '18' => $studentname2,
-                                  '19' => $student2->username,
-                                  '20' => userdate(time(), $dateformat),
-                                  '21' => 'On time',
-                                  '22' => $this->coursework->get_username_hash($submission2->allocatableid),
-                                  '23' => $feedback2->grade,
-                                  '24' => $assessorname1,
-                                  '25' => $assessorusername1,
-                                  '26' => userdate(time(), $dateformat),
-                                  '27' => $feedback3->grade,
-                                  '28' => $assessorname2,
-                                  '29' => $assessorusername2,
-                                  '30' => userdate(time(), $dateformat),
-                                  '31' => $feedback4->grade,
-                                  '32' => $assessorname2,
-                                 '33' => $assessorusername2,
-                                  '34' => userdate(time(), $dateformat),
-                                  '35' => $feedback4->grade];
-
+        $assessorsgrades = [
+            '0' => $studentname1,
+            '1' => $student1->username,
+            '2' => userdate(time(), $dateformat),
+            '3' => 'On time',
+            '4' => $coursework->get_username_hash($submission1->allocatableid),
+            '5' => $feedback1->grade,
+            '6' => $assessorname1,
+            '7' => $assessorusername1,
+            '8' => userdate(time(), $dateformat),
+            '9' => '',
+            '10' => '',
+            '11' => '',
+            '12' => '',
+            '13' => '',
+            '14' => '',
+            '15' => '',
+            '16' => '',
+            '17' => $feedback1->grade,
+            '18' => $studentname2,
+            '19' => $student2->username,
+            '20' => userdate(time(), $dateformat),
+            '21' => 'On time',
+            '22' => $coursework->get_username_hash($submission2->allocatableid),
+            '23' => $feedback2->grade,
+            '24' => $assessorname1,
+            '25' => $assessorusername1,
+            '26' => userdate(time(), $dateformat),
+            '27' => $feedback3->grade,
+            '28' => $assessorname2,
+            '29' => $assessorusername2,
+            '30' => userdate(time(), $dateformat),
+            '31' => $feedback4->grade,
+            '32' => $assessorname2,
+            '33' => $assessorusername2,
+            '34' => userdate(time(), $dateformat),
+            '35' => $feedback4->grade,
+        ];
         $this->assertEquals($assessorsgrades, $csvgrades);
     }
 }
diff --git a/tests/classes/export/grading_sheet_download_test.php b/tests/classes/export/grading_sheet_download_test.php
index 092aae25..9814d3be 100644
--- a/tests/classes/export/grading_sheet_download_test.php
+++ b/tests/classes/export/grading_sheet_download_test.php
@@ -24,8 +24,6 @@
 
 defined('MOODLE_INTERNAL') || die();
 
-global $CFG;
-
 /**
  * @property mixed feedback_data
  * @property mixed csv
@@ -48,6 +46,10 @@ public function setUp(): void {
         $this->teacher = $this->create_a_teacher();
         $this->otherteacher = $this->create_another_teacher();
 
+        // If we don't do this, we end up with the same cached objects for all tests and they may have incorrect/missing properties.
+        \mod_coursework\models\coursework::$pool = null;
+        \mod_coursework\models\submission::$pool = null;
+        \mod_coursework\models\feedback::$pool = null;
     }
 
     /**
@@ -57,38 +59,37 @@ public function setUp(): void {
     public function test_one_stage_no_allocations(): void {
 
         $generator = $this->getDataGenerator()->get_plugin_generator('mod_coursework');
-
-        /* @var mod_coursework_generator $generator */
-        $this->coursework = $generator->create_instance(['course' => $this->course->id,
+        $coursework = $generator->create_instance(['course' => $this->course->id,
                                                              'grade' => 100,
                                                              'numberofmarkers' => 1,
                                                              'deadline' => time() + 86400]);
-        $this->submission = new stdClass();
-        $this->submission->userid = $this->student->id;
-        $this->submission->allocatableid = $this->student->id;
-        $this->submission = $generator->create_submission($this->submission, $this->coursework);
+        $submission = new stdClass();
+        $submission->userid = $this->student->id;
+        $submission->allocatableid = $this->student->id;
+        $submission = $generator->create_submission($submission, $coursework);
 
         $student = $this->student;
-        $submission = $this->submission;
 
-        // headers and data for csv
+        // Headers and data for csv.
         $csvcells = ['submissionid', 'submissionfileid', 'name', 'username', 'submissiontime', 'singlegrade', 'feedbackcomments'];
 
         $timestamp = date('d_m_y @ H-i');
-        $filename = get_string('gradingsheetfor', 'coursework'). $this->coursework->name .' '.$timestamp;
-        $gradingsheet = new \mod_coursework\export\grading_sheet($this->coursework, $csvcells, $filename);
+        $filename = get_string('gradingsheetfor', 'coursework'). $coursework->name .' '.$timestamp;
+        $gradingsheet = new \mod_coursework\export\grading_sheet($coursework, $csvcells, $filename);
         $actualsubmission = $gradingsheet->add_cells_to_array($submission, $student, $csvcells);
 
         $studentname = $student->lastname .' '.$student->firstname;
 
-        // build an array
-        $expectedsubmission = ['0' => $submission->id,
-                                     '1' => $this->coursework->get_username_hash($student->id),
-                                     '2' => $studentname,
-                                     '3' => $student->username,
-                                     '4' => 'On time',
-                                     '5' => '',
-                                     '6' => ''];
+        // Build an array.
+        $expectedsubmission = [
+            '0' => $submission->id,
+            '1' => $coursework->get_username_hash($student->id),
+            '2' => $studentname,
+            '3' => $student->username,
+            '4' => 'On time',
+            '5' => '',
+            '6' => '',
+        ];
 
         $this->assertEquals($expectedsubmission, $actualsubmission);
     }
@@ -101,12 +102,15 @@ public function test_one_stage_no_allocations(): void {
     public function test_two_stages_with_allocations(): void {
         $generator = $this->getDataGenerator()->get_plugin_generator('mod_coursework');
 
-        /* @var mod_coursework_generator $generator */
-        $this->coursework = $generator->create_instance(['course' => $this->course->id,
-                                                              'grade' => 100,
-                                                              'numberofmarkers' => 2,
-                                                              'allocationenabled' => 1,
-                                                              'deadline' => time() + 86400]);
+        $coursework = $generator->create_instance(
+            [
+                'course' => $this->course->id,
+                'grade' => 100,
+                'numberofmarkers' => 2,
+                'allocationenabled' => 1,
+                'deadline' => time() + 86400,
+            ]
+        );
 
         // 2 assessors
         $assessor1 = $this->teacher;
@@ -115,18 +119,18 @@ public function test_two_stages_with_allocations(): void {
         $student1 = $this->student;
         $student2 = $this->otherstudent;
 
-        // submissions
+        // Submissions.
         $submission1 = new stdClass();
         $submission1->userid = $student1->id;
         $submission1->allocatableid = $student1->id;
-        $submission1 = $generator->create_submission($submission1, $this->coursework);
+        $submission1 = $generator->create_submission($submission1, $coursework);
 
         $submission2 = new stdClass();
         $submission2->userid = $student2->id;
         $submission2->allocatableid = $student2->id;
-        $submission2 = $generator->create_submission($submission2, $this->coursework);
+        $submission2 = $generator->create_submission($submission2, $coursework);
 
-        // Assessor2 feedback for student1
+        // Assessor2 feedback for student1.
         $feedbackdata1 = new stdClass();
         $feedbackdata1->submissionid = $submission1->id;
         $feedbackdata1->grade = 54;
@@ -135,7 +139,7 @@ public function test_two_stages_with_allocations(): void {
         $feedbackdata1->stage_identifier = 'assessor_2';
         $feedback1 = $generator->create_feedback($feedbackdata1);
 
-        // Assessor1 feedback for studen2
+        // Assessor1 feedback for student2.
         $feedbackdata2 = new stdClass();
         $feedbackdata2->submissionid = $submission2->id;
         $feedbackdata2->grade = 60;
@@ -144,7 +148,7 @@ public function test_two_stages_with_allocations(): void {
         $feedbackdata2->stage_identifier = 'assessor_1';
         $feedback2 = $generator->create_feedback($feedbackdata2);
 
-        // Assessor2 feedback for studen2
+        // Assessor2 feedback for student2.
         $feedbackdata3 = new stdClass();
         $feedbackdata3->submissionid = $submission2->id;
         $feedbackdata3->grade = 65;
@@ -153,7 +157,7 @@ public function test_two_stages_with_allocations(): void {
         $feedbackdata3->stage_identifier = 'assessor_2';
         $feedback3 = $generator->create_feedback($feedbackdata3);
 
-        // Agreed grade feedback
+        // Agreed grade feedback.
         $feedbackdata4 = new stdClass();
         $feedbackdata4->submissionid = $submission2->id;
         $feedbackdata4->grade = 62;
@@ -162,14 +166,14 @@ public function test_two_stages_with_allocations(): void {
         $feedbackdata4->stage_identifier = 'final_agreed_1';
         $feedback4 = $generator->create_feedback($feedbackdata4);
 
-        // headers and data for csv
+        // Headers and data for csv.
         $csvcells = ['submissionid', 'submissionfileid', 'name', 'username', 'submissiontime',
                            'assessor1', 'assessorgrade1', 'assessorfeedback1', 'assessor2', 'assessorgrade2', 'assessorfeedback2',
                            'agreedgrade', 'agreedfeedback'];
 
         $timestamp = date('d_m_y @ H-i');
-        $filename = get_string('gradingsheetfor', 'coursework'). $this->coursework->name .' '.$timestamp;
-        $gradingsheet = new \mod_coursework\export\grading_sheet($this->coursework, $csvcells, $filename);
+        $filename = get_string('gradingsheetfor', 'coursework'). $coursework->name .' '.$timestamp;
+        $gradingsheet = new \mod_coursework\export\grading_sheet($coursework, $csvcells, $filename);
         $actualsubmission1 = $gradingsheet->add_cells_to_array($submission1, $student1, $csvcells);
         $actualsubmission2 = $gradingsheet->add_cells_to_array($submission2, $student2, $csvcells);
         $actualsubmission = array_merge($actualsubmission1, $actualsubmission2);
@@ -180,36 +184,36 @@ public function test_two_stages_with_allocations(): void {
         $assessor1name = $assessor1->lastname .' '. $assessor1->firstname;
         $assessor2name = $assessor2->lastname .' '. $assessor2->firstname;
 
-        // build an array
-        $expectedsubmission = ['0' => $submission1->id,
-                                     '1' => $this->coursework->get_username_hash($student1->id),
-                                     '2' => $studentname1,
-                                     '3' => $student1->username,
-                                     '4' => 'On time',
-                                     '5' => $assessor1name,
-                                     '6' => '',
-                                     '7' => '',
-                                     '8' => $assessor2name,
-                                     '9' => $feedbackdata1->grade,
-                                     '10' => $feedbackdata1->feedbackcomment,
-                                     '11' => '',
-                                     '12' => '',
-                                     '13' => $submission2->id,
-                                     '14' => $this->coursework->get_username_hash($student2->id),
-                                     '15' => $studentname2,
-                                     '16' => $student2->username,
-                                     '17' => 'On time',
-                                     '18' => $assessor2name,
-                                     '19' => $feedbackdata2->grade,
-                                     '20' => $feedbackdata2->feedbackcomment,
-                                     '21' => $assessor1name,
-                                     '22' => $feedbackdata3->grade,
-                                     '23' => $feedbackdata3->feedbackcomment,
-                                     '24' => $feedbackdata4->grade,
-                                     '25' => $feedbackdata4->feedbackcomment ];
-
+        // Build an array.
+        $expectedsubmission = [
+            '0' => $submission1->id,
+            '1' => $coursework->get_username_hash($student1->id),
+            '2' => $studentname1,
+            '3' => $student1->username,
+            '4' => 'On time',
+            '5' => $assessor1name,
+            '6' => '',
+            '7' => '',
+            '8' => $assessor2name,
+            '9' => $feedbackdata1->grade,
+            '10' => $feedbackdata1->feedbackcomment,
+            '11' => '',
+            '12' => '',
+            '13' => $submission2->id,
+            '14' => $coursework->get_username_hash($student2->id),
+            '15' => $studentname2,
+            '16' => $student2->username,
+            '17' => 'On time',
+            '18' => $assessor2name,
+            '19' => $feedbackdata2->grade,
+            '20' => $feedbackdata2->feedbackcomment,
+            '21' => $assessor1name,
+            '22' => $feedbackdata3->grade,
+            '23' => $feedbackdata3->feedbackcomment,
+            '24' => $feedbackdata4->grade,
+            '25' => $feedbackdata4->feedbackcomment,
+        ];
         $this->assertEquals($expectedsubmission, $actualsubmission);
-
     }
 }
 
diff --git a/tests/classes/models/coursework_test.php b/tests/classes/models/coursework_test.php
index f5cea65c..74db5f66 100644
--- a/tests/classes/models/coursework_test.php
+++ b/tests/classes/models/coursework_test.php
@@ -27,8 +27,6 @@
 
 defined('MOODLE_INTERNAL') || die();
 
-global $CFG;
-
 /**
  * Class that will make sure the allocation_manager works.
  *
@@ -48,11 +46,8 @@ final class coursework_test extends advanced_testcase {
      * Makes us a blank coursework and allocation manager.
      */
     public function setUp(): void {
-
         $this->resetAfterTest();
-
         $this->course = $this->getDataGenerator()->create_course();
-        /* @var mod_coursework_generator $generator */
         $generator = $this->getDataGenerator()->get_plugin_generator('mod_coursework');
         $this->setAdminUser();
         $this->coursework = $generator->create_instance(['course' => $this->course->id, 'grade' => 0]);
@@ -97,7 +92,6 @@ public function test_get_allocation_manager(): void {
 
         // Now make a new coursework with a duff class name.
         $generator = $this->getDataGenerator()->get_plugin_generator('mod_coursework');
-        /* @var mod_coursework_generator $generator */
         $this->coursework = $generator->create_instance(['course' => $this->course->id, 'grade' => 0]);
         $this->coursework->assessorallocationstrategy = 'duffclass';
         $this->coursework->save();
@@ -107,7 +101,6 @@ public function test_get_allocation_manager(): void {
     }
 
     public function test_group_decorator_is_added(): void {
-        /* @var mod_coursework_generator $generator */
         $generator = $this->getDataGenerator()->get_plugin_generator('mod_coursework');
         $coursework = $generator->create_instance(['course' => $this->course->id,
                                                         'grade' => 0,
@@ -116,7 +109,6 @@ public function test_group_decorator_is_added(): void {
     }
 
     public function test_group_decorator_is_not_added(): void {
-        /* @var mod_coursework_generator $generator */
         $generator = $this->getDataGenerator()->get_plugin_generator('mod_coursework');
         $coursework = $generator->create_instance(['course' => $this->course->id,
                                                         'grade' => 0]);
@@ -158,10 +150,6 @@ public function test_get_user_group_with_grouping(): void {
     }
 
     public function test_get_user_group_with_wrong_grouping(): void {
-
-        /**
-         * @var mod_coursework_generator
-         */
         $generator = $this->get_coursework_generator();
 
         $this->create_a_student();
@@ -174,7 +162,7 @@ public function test_get_user_group_with_wrong_grouping(): void {
                                                         'use_groups' => true,
                                                         'grouping_id' => 543]);
 
-        $this->assertEquals(false, $coursework->get_student_group($this->student));
+        $this->assertFalse($coursework->get_student_group($this->student));
     }
 
     public function test_marking_stages_does_single_marker(): void {
@@ -242,7 +230,7 @@ public function test_file_types_commas_dots_stars(): void {
                             $coursework->get_file_options()['accepted_types']);
     }
 
-    public function test_groupings_appear_in_allocatabeles(): void {
+    public function test_groupings_appear_in_allocatables(): void {
 
         $this->create_a_course();
 
@@ -259,9 +247,9 @@ public function test_groupings_appear_in_allocatabeles(): void {
         $coursework->update_attribute('use_groups', 1);
 
         $allocatables = $coursework->get_allocatables();
-        $ispresent = is_numeric($group->id) && in_array($group->id, array_keys($allocatables));
+        $ispresent = is_numeric($group->id) && in_array((string)$group->id, array_keys($allocatables));
         $this->assertTrue(
-            $ispresent, "Actual array keys: ".implode(', ', array_keys($allocatables))
+            $ispresent, "Actual array keys: " . implode(', ', array_keys($allocatables))
         );
     }
 
diff --git a/tests/classes/models/deadline_extension_test.php b/tests/classes/models/deadline_extension_test.php
index d581f426..4dbdc86f 100644
--- a/tests/classes/models/deadline_extension_test.php
+++ b/tests/classes/models/deadline_extension_test.php
@@ -34,6 +34,11 @@ final class mod_coursework_models_deadline_extension_test extends advanced_testc
     public function setUp(): void {
         $this->resetAfterTest();
         $this->setAdminUser();
+
+        // If we don't do this, we end up with the same cached objects for all tests and they may have incorrect/missing properties.
+        \mod_coursework\models\coursework::$pool = null;
+        \mod_coursework\models\submission::$pool = null;
+        \mod_coursework\models\feedback::$pool = null;
     }
 
     public function test_create(): void {
@@ -69,10 +74,12 @@ public function test_user_extension_allows_submission_when_passed(): void {
 
     public function test_get_coursework(): void {
         $coursework = $this->create_a_coursework();
-        $params = ['allocatableid' => 3,
-                        'allocatabletype' => 'user',
-                        'courseworkid' => $coursework->id,
-                        'extended_deadline' => strtotime('- 1 week')];
+        $params = [
+            'allocatableid' => 3,
+            'allocatabletype' => 'user',
+            'courseworkid' => $coursework->id,
+            'extended_deadline' => strtotime('- 1 week'),
+        ];
         $extension = deadline_extension::create($params);
         $this->assertEquals($extension->get_coursework(), $coursework);
     }
diff --git a/tests/classes/models/submission_test.php b/tests/classes/models/submission_test.php
index 38469a6a..69bebbd2 100644
--- a/tests/classes/models/submission_test.php
+++ b/tests/classes/models/submission_test.php
@@ -27,8 +27,6 @@
 
 defined('MOODLE_INTERNAL') || die();
 
-global $CFG;
-
 /**
  * Class that will make sure the allocation_manager works.
  * @group mod_coursework
@@ -45,12 +43,15 @@ public function setUp(): void {
         $this->resetAfterTest();
 
         $this->course = $this->getDataGenerator()->create_course();
-        /* @var mod_coursework_generator $generator */
         $generator = $this->getDataGenerator()->get_plugin_generator('mod_coursework');
         $this->setAdminUser();
         $this->coursework = $generator->create_instance(['course' => $this->course->id, 'grade' => 0]);
         $this->redirectMessages();
         $this->preventResetByRollback();
+
+        // If we don't do this, we end up with the same cached objects for all tests and they may have incorrect/missing properties.
+        \mod_coursework\models\coursework::$pool = null;
+        \mod_coursework\models\user::$pool = null;
     }
 
     /**
@@ -99,7 +100,6 @@ public function test_save_courseworkid(): void {
     }
 
     public function test_group_decorator_is_not_added(): void {
-        /* @var mod_coursework_generator $generator */
         $generator = $this->getDataGenerator()->get_plugin_generator('mod_coursework');
         $coursework = $generator->create_instance(['course' => $this->course->id,
                                                         'grade' => 0]);
@@ -113,23 +113,14 @@ public function test_group_decorator_is_not_added(): void {
     }
 
     public function test_get_allocatable_student(): void {
-
         $student = $this->create_a_student();
-        /**
-         * @var submission $submission
-         */
         $submission = submission::build(['allocatableid' => $student->id, 'allocatabletype' => 'user']);
         $this->assertEquals($student, $submission->get_allocatable());
     }
 
     public function test_get_allocatable_group(): void {
-
         $group = $this->create_a_group();
-        /**
-         * @var submission $submission
-         */
-        $submission = submission::build(['allocatableid' => $group->id,
-                                              'allocatabletype' => 'group']);
+        $submission = submission::build(['allocatableid' => $group->id, 'allocatabletype' => 'group']);
         $this->assertEquals($group, $submission->get_allocatable());
     }
 
@@ -141,15 +132,9 @@ public function test_extract_extenstion_from_filename(): void {
 
     public function test_publish_updates_grade_timemodified(): void {
         global $DB;
-
-        /* @var mod_coursework_generator $generator */
         $generator = $this->getDataGenerator()->get_plugin_generator('mod_coursework');
         $student = $this->create_a_student();
-        /**
-         * @var submission $submission
-         */
-        $submissiondata = ['allocatableid' => $student->id,
-                                              'allocatabletype' => 'user'];
+        $submissiondata = ['allocatableid' => $student->id, 'allocatabletype' => 'user'];
         $submission = $generator->create_submission($submissiondata, $this->coursework);
         $this->coursework->update_attribute('numberofmarkers', 1);
         $feedbackdata = new stdClass();
@@ -157,10 +142,6 @@ public function test_publish_updates_grade_timemodified(): void {
         $feedbackdata->grade = 54;
         $feedbackdata->assessorid = 4566;
         $feedbackdata->stage_identifier = 'assessor_1';
-
-        /**
-         * @var feedback $feedback
-         */
         $feedback = $generator->create_feedback($feedbackdata);
 
         sleep(1);
@@ -175,7 +156,9 @@ public function test_publish_updates_grade_timemodified(): void {
 
         $submission->publish();
 
-        $gradeitem = $DB->get_record('grade_items', ['itemtype' => 'mod', 'itemmodule' => 'coursework', 'iteminstance' => $this->coursework->id]);
+        $gradeitem = $DB->get_record(
+            'grade_items', ['itemtype' => 'mod', 'itemmodule' => 'coursework', 'iteminstance' => $this->coursework->id]
+        );
         $grade = $DB->get_record('grade_grades', ['itemid' => $gradeitem->id, 'userid' => $student->id]);
         $gradetimemodified = $grade->timemodified;
 
@@ -186,14 +169,9 @@ public function test_publish_updates_grade_timemodified(): void {
     public function test_publish_updates_grade_rawgrade(): void {
         global $DB;
 
-        /* @var mod_coursework_generator $generator */
         $generator = $this->getDataGenerator()->get_plugin_generator('mod_coursework');
         $student = $this->create_a_student();
-        /**
-         * @var submission $submission
-         */
-        $submissiondata = ['allocatableid' => $student->id,
-                                 'allocatabletype' => 'user'];
+        $submissiondata = ['allocatableid' => $student->id, 'allocatabletype' => 'user'];
         $submission = $generator->create_submission($submissiondata, $this->coursework);
         $this->coursework->update_attribute('numberofmarkers', 1);
         $feedbackdata = new stdClass();
@@ -201,39 +179,28 @@ public function test_publish_updates_grade_rawgrade(): void {
         $feedbackdata->grade = 54;
         $feedbackdata->assessorid = 4566;
         $feedbackdata->stage_identifier = 'assessor_1';
-
-        /**
-         * @var feedback $feedback
-         */
         $feedback = $generator->create_feedback($feedbackdata);
 
         $submission->publish();
         $feedback->update_attribute('grade', 67);
         $submission->publish();
 
-        $gradeitem = $DB->get_record('grade_items',
-                                      ['itemtype' => 'mod',
-                                            'itemmodule' => 'coursework',
-                                            'iteminstance' => $this->coursework->id]);
-        $grade = $DB->get_record('grade_grades',
-                                 ['itemid' => $gradeitem->id,
-                                       'userid' => $student->id]);
+        $gradeitem = $DB->get_record(
+            'grade_items',
+                  ['itemtype' => 'mod', 'itemmodule' => 'coursework', 'iteminstance' => $this->coursework->id]
+        );
+        $grade = $DB->get_record(
+            'grade_grades',
+            ['itemid' => $gradeitem->id, 'userid' => $student->id]);
 
         $this->assertEquals(67, $grade->rawgrade);
-
     }
 
     public function test_publish_sets_grade_timemodified(): void {
         global $DB;
-
-        /* @var mod_coursework_generator $generator */
         $generator = $this->getDataGenerator()->get_plugin_generator('mod_coursework');
         $student = $this->create_a_student();
-        /**
-         * @var submission $submission
-         */
-        $submissiondata = ['allocatableid' => $student->id,
-                                 'allocatabletype' => 'user'];
+        $submissiondata = ['allocatableid' => $student->id, 'allocatabletype' => 'user'];
         $submission = $generator->create_submission($submissiondata, $this->coursework);
         $this->coursework->update_attribute('numberofmarkers', 1);
         $feedbackdata = new stdClass();
@@ -247,16 +214,12 @@ public function test_publish_sets_grade_timemodified(): void {
         sleep(1); // Make sure we do not just have the same timestamp everywhere.
         $submission->publish();
 
-        $gradeitem = $DB->get_record('grade_items',
-                                      ['itemtype' => 'mod',
-                                            'itemmodule' => 'coursework',
-                                            'iteminstance' => $this->coursework->id]);
-        $grade = $DB->get_record('grade_grades',
-                                 ['itemid' => $gradeitem->id,
-                                       'userid' => $student->id]);
+        $gradeitem = $DB->get_record(
+        'grade_items',
+              ['itemtype' => 'mod', 'itemmodule' => 'coursework', 'iteminstance' => $this->coursework->id]
+        );
+        $grade = $DB->get_record('grade_grades', ['itemid' => $gradeitem->id, 'userid' => $student->id]);
         $timemodified = $grade->timemodified;
-
         $this->assertEquals($feedback->timemodified, $timemodified);
     }
-
 }
diff --git a/view.php b/view.php
index b8ae5bfe..5b07e62d 100644
--- a/view.php
+++ b/view.php
@@ -301,7 +301,7 @@
 
 if ($exportgrades) {
 
-    // Headers and data for csv
+    // Headers and data for csv.
     $csvcells = ['name', 'username', 'idnumber', 'email'];
 
     if ($coursework->personal_deadlines_enabled()) {