diff --git a/src/assets/wise5/classroomMonitor/classroom-monitor.component.ts b/src/assets/wise5/classroomMonitor/classroom-monitor.component.ts
index fd0ae2b7573..0eae5172925 100644
--- a/src/assets/wise5/classroomMonitor/classroom-monitor.component.ts
+++ b/src/assets/wise5/classroomMonitor/classroom-monitor.component.ts
@@ -66,6 +66,7 @@ export class ClassroomMonitorComponent implements OnInit {
 
   ngOnDestroy(): void {
     this.subscriptions.unsubscribe();
+    this.dataService.clearCurrentPeriod();
   }
 
   private initializeNotebook(): void {
diff --git a/src/assets/wise5/services/teacherDataService.ts b/src/assets/wise5/services/teacherDataService.ts
index 43eb73272d7..c7a5329b985 100644
--- a/src/assets/wise5/services/teacherDataService.ts
+++ b/src/assets/wise5/services/teacherDataService.ts
@@ -683,6 +683,10 @@ export class TeacherDataService extends DataService {
     }
   }
 
+  clearCurrentPeriod(): void {
+    this.currentPeriod = null;
+  }
+
   getCurrentPeriod() {
     return this.currentPeriod;
   }