If you’re having problems and Apple TV still doesn’t respond after restarting, try resetting Apple TV to its factory settings. When you reset Apple TV, all data is erased, including your accounts and configuration.
You can also reset your Apple TV and update its software at the same time.
You can use your iPhone or iPad to set up your Apple TV for faster recovery. See the Apple Support article Apple TV Support.
If you have an Apple TV HD and a Mac with macOS Catalina or later: Disconnect the power and HDMI cables from Apple TV. Connect one end of a USB-C cable (sold separately) to Apple TV and the other end to your computer. Open the Finder on your computer, select Apple TV in the sidebar, then select Restore. If that doesn’t work, contact select Reset and Update.
Selecting this option restores your Apple TV to factory settings, erases all settings and information, and updates to the latest tvOS version.