all4 app not loading

What is the model Apple TV box? Identify your Apple TV model - Apple Support

• Verify that the system software is up-to-date (v16.2 as of today). Update your Apple TV - Apple Support
• Verify that your apps are up-to-date. Set automatic app updates as new versions become available. Check manually through the on-device App Store (it should say Open or Update for these apps). App versions and system software versions go together for compatibility, so both matter. Set up automatic updates - Apple TV user guide - Apple Support

Else try this for any misbehaving app:

1. Force-quit the app, then relaunch and try again.
2. If the issue persists, force-quit the app, restart the device, then relaunch and try again.
3. If the issue still persists, delete the app, re-download and try again.
4. If the issue still persists after that, then contact the app developer for further assistance.

It sounds like the apps were not fully installed. Try to delete and try again. See if you are able to use the pre-installed apps from Apple (ie Apple TV app). If you had already installed the Speedtest app that is a good place to check the current internet connection. You can also try rebooting the Apple TV.