The channel Up Down button on Apple TV remote, remote App, or any programmable Universal remote won’t work. The DirecTV app for Apple TV offers a guide and channel lineup, but the app doesn’t allow the up/down function
DirecTV Apple TV app channel button
Hello @NeoStarburst, thank you for your post. For help with the Apple TV Remote, please post in the Apple Support Community. The Apple Developer Forums are for questions about APIs and features intended specifically for developers.