You can troubleshoot by following these steps:

1. Ensure that the two magnetic sensors are close to each other, within 3 cm (1 inch), when the garage door is fully closed and vice versa.

2. Unplug and plug the sensor cables, checking for any wire damage.

3. Do not install the sensors directly on any metal rails. For instance, you can use materials such as PVC to isolate the sensors from metal to avoid magnetic interference.

4. Factory reset the smart garage door opener and set it up from scratch.

5. Completely reinstall the Meross app.