Sometimes iPhone 11 Pro zoom turns jumpy/jittery when it transitions between ultrawide <--> wide angle camera. This is reproducible with native camera app on iOS 13.1 as well. I have filed a bug (FB7326554) to highlight the issue which has a screen recording from native camera app as well.
Here is YouTube video of the issue:
https://www.youtube.com/watch?v=79e9Sl6nXEw
Apple Engineers -- any known workaround in AVFoundation for this serious issue? Or is this an issue with the device I have?