I have a similar problem, the gnome shell crashes, part of the UI gets unresponsive, especially the dock is not disappearing, and overlaps over the applications. When I lock the session, the dock is still visible and programs can be started in locked state!
** Attachment added: "log.txt" https://bugs.launchpad.net/ubuntu/+source/gnome-shell/+bug/1799242/+attachment/5205008/+files/log.txt -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1799242 Title: gnome-shell crashes when locking screen while dock widget is in focus To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-shell/+bug/1799242/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs