Simple tvOS UIButton is not working

You shouldn't be using ".TouchDown" or ".TouchUpInside" on tvOS, since that doesn't do what you might expect: you probably want to use "UIControlEvents.PrimaryActionTriggered" instead.

TouchUpInside is triggered by actual touches, which isn't really what happen. If you want the Select button press on the remote to trigger your button, you should use PrimaryActionTriggered.