I know it's just a visual thing but iPads that have been focused that have apps in folders end up being greyed out. Is there a way to not have this happen?
Have you tried turning it off and on again?
I had some Faculty explain the same situation. It's only doing it to some folders.
That's happening to us using Apple Classroom too, occasionally after a kid has had their screen locked and/or viewed by the teacher their folders will gray out. Usually fixes by restarting the iPad.