Blank screen but sound on Apple TV

Trailers and ‘previously on’ picture works fine but when desired tv show starts I have a blank screen but sound. Any suggestions to remedy? If I uninstall the app then reinstall it works fine for a while but then the same error occurs. No issue on lg tv if casting from phone or using that lg app and not using Amazon so it’s something to do with Amazon fire tv and Apple app. Strange that trailers work fine but episodes don’t. I have the fire tv hdmi plugged in to hue sync box which then has hdmi connection to tv.