Fix incorrect warning

Clear the incoming serial buffer before writing each command so the correct echo is read

MaxLairInstance.py

@@ -361,6 +361,9 @@ def push_buttons(self, *commands: Tuple[str, float]) -> None:
             # then we release the lock so the display thread can run while we complete the button press and subsequent delay
             self.lock.release()
 
+            # Clear extra characters from the serial buffer
+            self.com.reset_input_buffer()
+
             # then we send the command to the microcontroller using the serial port
             self.com.write(character)