Hello susja,
It sounds like you are noticing the lack of effects with Dock and Recent app on your iPad, right? Other than restarting your iPad, have you tried to turn off Stage Manager and turn it back on?
This link may help answer your question:
Move, resize, and organize windows with Stage Manager on iPad - Apple Support
"Turn Stage Manager on or off
With your iPad in landscape orientation, open Control Center, then tap .
The window you’re working in is positioned prominently in the center of the screen, at a size that makes it easy to work with. All the other apps move left and form a list of recent apps along the left side of the screen."
Regards.