Black screen on Apple TV app using Firestick

I am trying to use my Apple TV app on my fire stick. I get the Home Screen fine but when I select a film or program I can watch the trailer but when the program starts I have sound but only a black screen. I have checked the app is up to date, I’ve uninstalled and reinstalled the app, restarted it and everything else that’s been suggested but nothing is working. Any suggestions?