Hi Chris_V89...
Thank you for your reply. When I set up Stage Manager, I used the link you sent to set it up. I went through it again just now and experimented by turning off "all at once" and turned on "one at a time". Otherwise, I didn't see any other settings I had done wrong. I have used the drag feature when I need my calculator while doing banking. Works great. Changing my thumbnails works great. My issue is the timing of the apps and thumbnails not being visible, as in disappearing from my screen at odd times.
When an app isn't visible because it's hidden or hasn't been used recently Sometimes when I walk into the kitchen for a glass of water, for instance, when I come back (under 5 minutes), the app has disappeared into the top of my screen leaving a thin grey strip, which, when tapped, slides back onto my desktop. The thumbnails are gone, too, off to the left of the screen, but also return. It's easy enough to tap on the grey strip and everything is back.
However, yesterday I was in the middle of typing a sentence in an email and the app disappeared into the top of the screen. Okay, but doesn't follow that it "hasn't been used recently". I was in the process of using the app. I had not touched any command keys of any kind. And, interestingly, just now, while I PAUSED for a few seconds to think of the next thing to type, it did the same thing....app disappeared at the top of my screen. I find this odd. And annoying.
I did upgrade to 13.3 yesterday. I also called Apple Support and allowed them access to my screen while my app was conveniently in the act of disappearing, but when asked, was told nobody had called about this issue and the person seemed baffled. As am I. The tech person had me shut my computer down and reboot it. I knew that wouldn't help because I'd tried that, and it didn't help.
I'm puzzled because of the timing of the apps and thumbnails disappearing, especially doing it while I'm typing an email, for instance. (And it just did it again). Having it happen every few minutes while working on my computer is not working for me. :-( I'm calling gremlins.
Anyway, Chris_V89, thank you for giving it a shot. I do appreciate the time you took to read, copy, paste, and try to fix this issue. Hope you have a good day!