Important: When you set up your AT&T TV device at home, that location becomes the residential, non-mobile internet network associated with your device. This is called your home Wi-Fi network. Accessing the AT&T TV app on your Apple TV will also be limited to your home Wi-Fi network. You can change your home Wi-Fi network up to 4 times within a 12-month period by relocating your AT&T TV device.
Sound and data issues
Check sound settings
On your Apple TV, select Settings, then Audio & Video.
Audio Out is set to Apple TV.
Sound Effects and Music are set to on.
In Surround Sound settings, make sure that Best Quality Available is selected.
Clear AT&T TV app cache and data
From the Apple TV home menu, select Settings, then Apps and Manage Installed Apps.