Just update the Ring app for iOS version 5.21.0 and now you can’t pinch to zoom on live view any more.
This is a fantastic function and one you definitely need, you still can pinch to zoom on playback.
I have tried the Ring app on a different iPhone that has still got the old version 5.20.0 and the pinch to zoom on live view is still working perfectly on the old iOS version so it’s definitely a issue with the new iOS update version 5.21.0
The only way to pinch to zoom on live view just now is to download the Rapid Ring app from the App Store, until Ring fixings the issue everybody is having, it does not have all the functions of the original ring app. But you can pinch to zoom on live view.