To resolve the issue of the "Back to previous screen" button not functioning in the YPT app, follow these steps:

1. Restart the YPT App:
- Close the YPT app completely (ensure it is not running in the background).
- Reopen the app to see if the back button is working.

2. Check for App Updates:
- Open the Google Play Store on your Android device.
- Search for the YPT app.
- If an update is available, tap "Update" to install the latest version. Updated apps often come with bug fixes that may resolve functional issues.

3. Clear App Cache:
- Go to Settings on your Android device.
- Navigate to Apps or Application Manager.
- Find and select the YPT app.
- Select Storage, then tap Clear Cache. This can help eliminate any temporary files that might be causing the issue.

4. Check for Device Updates:
- Open Settings on your device.
- Scroll down to System and tap on System updates.
- If an update is available, download and install it. Keeping your device up-to-date can help with app compatibility.

5. Reboot Your Device:
- Sometimes a simple reboot can resolve glitches.
- Hold down the power button and select Restart. After the device restarts, check if the back button works in the YPT app.

6. Reset App Preferences:
- Go to Settings.
- Tap on Apps or Application Manager.
- Tap the three vertical dots in the top corner and select Reset app preferences. This option resets all disabled apps, notifications, and default applications for certain actions.

7. Reinstall the YPT App:
- Uninstall the YPT app by long-pressing its icon and selecting Uninstall.
- Reinstall it from the Google Play Store and check if the issue persists.

8. Contact Support:
- If none of the above solutions work, consider reaching out to YPT support for further assistance.

By following these steps, you should be able to troubleshoot and resolve the issue with the back button in the YPT app. If the problem continues, it may be a bug that requires a future update to address it - learn more - learn more - learn more - learn more - learn more.