It just happened to me, using X.org with and AMD graphics card and no extra extensions enabled. Upgraded from Ubuntu 20.10 to 21.04.
** Attachment added: "system-info" https://bugs.launchpad.net/ubuntu/+source/gnome-shell-extension-ubuntu-dock/+bug/1922353/+attachment/5495658/+files/system-info -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to gnome-shell in Ubuntu. https://bugs.launchpad.net/bugs/1922353 Title: Overview sometimes fails to appear or disappear in 21.04 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-shell/+bug/1922353/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs