What is your model Apple TV box?
Identify your Apple TV model - Apple Support
Find your Apple TV model number - Apple Support
- Try the steps as mentioned in: If your Apple TV can't connect to Wi-Fi - Apple Support
- Try the ‘Other…’ option instead of selecting a listed discovered network. Especially if the password has been changed while the same SSID network name is in use.
- For Apple TV (4th generation or earlier), verify that the router or access point isn’t set to use WPA3, as only device models from ~2018 or later support that. Instead use ‘WPA2/WPA3 Transitional’. Some users report that they had to set ‘WPA2’-only first.