On what brand and model TV is this happening? Troubleshooting may have platform-specific aspects.
In general:
- Check for TV system software updates. Apply if available;
- Try a TV restart (not just standby-wake). If that can’t be done in software, then unplug from power for a while;
- Try a reset of the Apple TV app;
- Try a delete and re-install of the Apple TV app (if supported);
- Try deleting caches, if your TV has a manual configuration for that;
- Try resetting the TV network settings.
- Verify the TV’s date and time and timezone settings, as secure communications (SSL, TLS, HTTPS) require fairly accurate timestamps.