To resolve the issue where Netflix will not play on the Hearo app and requests that it be watched in the Netflix app, follow these steps:

1. Sign Out and Sign Back In: Since you've already signed out, ensure that you completely exit from both the Hearo app and Netflix app. Then, restart your device.

2. Clear Cache and Data (if applicable):
- Open your device's settings.
- Go to Apps or Applications.
- Find Hearo and Netflix.
- Select both apps, then choose Clear Cache and Clear Data.

3. Reinstall the Apps: Uninstall both the Hearo app and the Netflix app from your device. After that:
- Go to the app store (Google Play Store for Android devices or the App Store for iOS).
- Reinstall both apps.

4. Reconnect the Apps: Open the Hearo app first and sign in. After that, access Netflix through Hearo. If you don't see an option to re-sync Netflix, look for an option within the Hearo app settings.

5. Network Connection Check: Ensure that your internet connection is stable. You can restart your router if needed.

6. Restart Your Device: Power off your device completely, wait for about 30 seconds, and turn it back on. This can refresh the system and resolve minor glitches.

7. Contact Support: If the issue persists after trying these steps, you may need to contact the support teams of either Hearo or Netflix for assistance.

These steps should address the compatibility problem between the Hearo app and Netflix. Implement them in order and check after each step if the issue is resolved.

For more troubleshooting tips, you can visit the Netflix Help Center on video issues - learn more.