I retract the last claim. The bug is there, but it is not always there. Specifically, sometimes I encounter the bug, kill and restart the app, and the same screen setup where it was buggy is now just fine.
When it goes wrong, it’s like it loses track of where the bottom of the screen is supposed to be. And if I open up a keyboard, the whole display scrolls up, even when it shouldn’t, and the spot the program is trying to work in is above the actual work area.
And here, after that issue I turned the screen sideways after closing the keyboard, and you see the issue.
One detail: Im using a Google virtual keyboard in place if the standard. Dimensions are identical but maybe this makes a difference?