The fourth-generation Apple TV 4K began arriving to customers, and some users found that the YouTube app was not working on the new device. Users who opened the app saw an error and, in some cases, a black screen with a QR code alongside the message "YouTube is not yet available on this device."
Apple's suggested fixes start with making sure tvOS 27.2 is installed, which can be checked under Settings, then System, then Software Updates. If the problem persists, uninstalling and reinstalling the YouTube app is the last recommended step.S1