If the myTuner Radio app stops playing after 15 minutes, you can try the following troubleshooting steps to resolve the issue:

1. Check Battery Optimizations:
- Go to your device's Settings.
- Navigate to Apps and find myTuner Radio.
- Select Battery and ensure that battery optimization is turned off for the app. This will prevent the app from being terminated to save battery.

2. Network Connection:
- Ensure that you have a stable internet connection. Sometimes, connection issues may cause the app to stop playing. Switch between Wi-Fi and mobile data or restart your router if necessary.

3. Update the App:
- Check the Google Play Store to see if there is an update available for myTuner Radio. Keeping the app updated can help eliminate bugs that might cause playback issues.

4. Clear App Cache and Data:
- Go to Settings > Apps.
- Find myTuner Radio, select it, and then tap on Storage.
- Clear the Cache and Data. Note that clearing data may remove saved settings and preferences.

5. Reinstall the App:
- Uninstall myTuner Radio and then reinstall it from the Google Play Store. This can resolve issues that stem from a bad installation or corrupted files.

6. Test with Other Apps:
- Confirm if the issue is specific to myTuner Radio by testing other radio apps. If those also stop after a similar period, it might be an OS or device issue rather than the app itself.

7. Check for Device Sleep Settings:
- Some devices have settings that cause apps to stop functioning when the screen goes idle. Ensure that your device's sleep settings are configured to prevent this while using myTuner Radio.

8. Review App Permissions:
- Ensure that myTuner Radio has the necessary permissions to run smoothly. Go to Settings > Apps > myTuner Radio > Permissions and check that all required permissions are granted.

9. Consult Community Forums:
- If the problem persists, visiting community forums (like those on Reddit) may provide insights or solutions from other users who have experienced the same issue - learn more - learn more - learn more.

By following these steps, you can troubleshoot the issue with myTuner Radio stopping playback after 15 minutes.