Hi! I understand the issue you’re facing: after completing an exercise in the Rhythm Trainer app, it initially shows a green tick (which means success), but then it switches to a red cross and keeps repeating. Let’s try to get to the bottom of this together.

To start, could you please tell me:

1. Are you connected to the internet during the exercise?
2. Have you noticed this happening with all exercises or just specific ones?
3. Have you tried closing and reopening the app or restarting your device?
4. Is your app updated to the latest version available on your Android device?

These details will help me guide you better. In the meantime, here’s a step-by-step approach we can try:

1. Restart the App: Fully close the Rhythm Trainer app (swipe it away from recent apps) and then reopen it. Sometimes a quick refresh resolves temporary glitches.

2. Check Internet Connection: Ensure your device is connected to stable WiFi or mobile data. The app might be syncing your progress, and intermittent connection could cause status flickering.

3. Clear Cache: On Android 10 (your OS version), go to Settings > Apps > Rhythm Trainer > Storage > Clear Cache. This removes temporary files that could be corrupted without deleting your data.

4. Update the App: Go to Google Play Store and check if there’s an update available for Rhythm Trainer. Developers routinely release fixes for such issues.

5. Re-login: If the app has a login, try logging out and back in to refresh your user session.

If you have already tried these steps or the problem persists, it might be related to a syncing or server issue that causes the app to reconsider your exercise result, switching the tick to cross as it tries to revalidate your performance.

Please let me know what you’ve already tried and any other specifics you notice about when this happens. I’ll help you from there!