I’m starting to suspect there is a bug in GNOME Shell where the overview occasionally gets “stuck”. No key press or widget click will exit the overview mode. I have to log out and log back in. Launching new windows still works, but the window immediately gets arranged into the overview.
I first noticed this behavior when I tried out the Pop!_OS 21.04 beta, and dismissed it as a bug in the beta. But now I’ve seen it twice in Ubuntu 21.04 proper. Has anyone else noticed this behavior?
You can run ubuntu-bug gnome-shell to report the issue. People can then mark themselves as affected or not on Launchpad.
Can confirm that I have also encountered this issue in 21.04. Also, I have never experienced anything similar in the previous releases, so it looks to be a new issue in 21.04.
@spc, if you report the issue on Launchpad as @rs2009 recommends, please cite the link to the new bug ticket here.
Just a tiny workaround: instead of logging out and logging back in, you can press Alt+F2, type ‘r’ in the invoked command line and press Enter. This restarts GNOME Shell. In my case, it helped.
I guess, here is the issue ticket:
Nice find on the bug link. That’s exactly the behavior I’m seeing.
I can’t restart the shell. I’m using the wayland session (by default). 
Been running Gnome on Wayland on Hirsute for quite some time now, never happened here… (Upgraded Mesa though)
Oh yes, right. Sorry, I forgot that the restart doesn’t work on Wayland. Indeed, I use Xorg session.
People are reporting this bug with focal as well.
No they’re not as far as I can see. Anyone using 21.04 should use bug 1922353. Anyone using 20.04 should open a new bug by running:
ubuntu-bug gnome-shell
The issue(s) shouldn’t really be discussed here any further.
And anyone using PopOS shouldn’t report the problem to Ubuntu at all, because PopOS does not use Ubuntu packages.