I hit the same issue in Ubuntu 24.04. I noticed that after a resume from the suspend mode, I wasn't prompted to enter a password and was logged in automatically (which isn't too safe). Nor "Super + L" worked.
The setting "disable-lock-screen" was "true" from some reason. "gsettings set org.gnome.desktop.lockdown disable-lock-screen false" solved the issue. But I have no idea why the setting was "true". I installed a fresh OS a few days ago and I'm not aware that I changed the option from "false" to "true". Maybe it was changed by an upgrade or installation of some tool .....? Nevertheless it's working now. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1889277 Title: lock screen not working, neither Win+L nor suspend works to lock the screen To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-screensaver/+bug/1889277/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs