Hey jamesgrainger120,
It appears that the Apple TV app is unexpectedly quitting on your devices. Please check out the steps below and see if that might help:
Before you sell or give away your device or uninstall the Apple TV app or Apple TV+ app, you should reset the Apple TV app and Apple TV+ app. Resetting the Apple TV app and Apple TV+ app signs you out of your account, removes your personal information, and restores the apps to their original settings.
If you reset the Apple TV app and Apple TV+ app on a smart TV that's also signed in to the Apple Music app, then the Apple Music app will also be restored to its original settings.
- Open the Apple TV app or Apple TV+ app.
- Go to Settings.
- On your smart TV, choose Reset Apple TV app and Apple Music, or Reset Apple TV+ app. Then confirm your choice.
- On your streaming device or game console, choose Reset Apple TV app or Reset Apple TV+ app. Then confirm your choice."
The steps are from this article: Get the Apple TV app or Apple TV+ app on your smart TV, streaming device, or game console - Apple Support
Take care.