I installed dash-to-dock to test this. I locked the PC and unlocked it without an issue. The dock didn't appear in the lock screen.
gnome-shell-extension-ubuntu-dock: Installed: 63ubuntu1.18.10.1 Candidate: 63ubuntu1.18.10.1 ** Tags removed: verification-needed verification-needed-cosmic ** Tags added: verification-done verification-done-cosmic -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1769383 Title: Ubuntu dock/launcher is shown on the lock screen To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-shell/+bug/1769383/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs