I don't know if this problem has been reported before but I can say that it's been around for years in both iOS and iPadOS.
I like to use full screen zoom to help with reading and naturally also use Smart Typing and Follow Focus.
When you select a text field, the keyboard pops up and the Full Screen Zoom temporarily switches to a Windowed Zoom view that follows the text. Once the keyboard drops away, the Zoom Window then reverts back to Full Screen. At least, that's what's supposed to happen.
Since back when I used an iPhone X, after a certain major OS update (I forget which) the Follow Focus Zoom Window would get 'stuck' in the Windowed view and not revert. The easiest way to put it back in full screen was to return to the home screen.
It occurs most frequently in the Messages and YouTube apps but can also occur in Safari and others.
The issue became such a nuisance that I switched back to an Android Phone (which doesn't have such a problem). I still use an iPad though and the bug never seems to get fixed. Honestly, I wouldn't mind going back to an iPhone for better synergy but am afraid of this issue once again getting in the way.
I did report it to Apple though that was a couple of years or so ago at this point.
Has anyone else encountered this issue?
I would include video but i need to figure out the best way to film it as, unfortunately, iPad screen record doesn't show any accessibility features in screen recordings.
UPDATE: Here's a link to 3 video clips demonstrating the issue: