My new Xbox controller will pair with my 4k AppleTV, but the controls do not function.

I just got an Xbox controller specifically to use with Apple Arcade on my 4k AppleTV. The controller is brand new. It will pair with the AppleTV without problem, but once paired it does nothing else. None of the controls function at all. I've watched any number of YouTube videos and can see that as soon as the devices are paired, you should be able to use the Xbox controller to navigate, but mine does absolutely nothing. Help!

I don't have an Xbox, so I don't know how I would check for a firmware update on the controller. It's brand new. I'm running tvOS version 14.2 (the latest).