Apple TV App Black Screen

[spireitestone]

I had a new Sky Q box yesterday installed by a Sky engineer. It was a replacement for a previous Sky Q box as when streaming the picture was distorted or screen was going green. 
everything is ok now apart from Apple TV app - the screen is going black every 10 seconds when watching any programme. All other apps playing fine eg Disney+, Netflix etc. 

Ive changed the HDMI cable but the issue is the same