Apple TV will not contact to any network
Apple TV will not connect to network despite tv beside it connecting.
phone and iPad also.
neither wifi or Ethernet
Apple TV 4K (2nd generation)
Please see the troubleshooting steps in:
If your Apple TV can't connect to Wi-Fi - Apple Support
Do try restarting the router for a fresh connection attempt.
Is this a regular home network without captive network portal?
Do you get an error message? What does it say?