Ring doorbell showing black screen in App on Live view

Recently, my Ring Doorbell has started to show just a black screen in the Ring app when I click on Live View? It doesn’t seem to matter whether I'm at home on Wi-Fi or logging in on 4G away from home? When I stop the Live View I can go to History in the App and can see the footage perfectly well and seems to only affect the Live View? Any ideas anyone. I've rebooted the Ring Doorbell, and everything else is working apart from this. Quick update on this. I've found that the black screen is when my phone is in the portrait position, and if i rotate my phone to landscape it actually then works? If I then return the phone back to the portrait position it continues to work. So it only seems to be an issue with the initial portrait screen??