If you can still move the mouse then Xorg hasn't crashed, but gnome- shell has.
Next time the problem happens, please: 1. Wait 10 seconds. 2. Reboot. 3. Run: journalctl -b-1 > prevboot.txt 4. Attach the resulting text file here. 5. Also follow these instructions to report any recent crashes: https://wiki.ubuntu.com/Bugs/Responses#Missing_a_crash_report_or_having_a_.crash_attachment ** Package changed: xorg (Ubuntu) => ubuntu ** Changed in: ubuntu Status: New => Incomplete ** Summary changed: - Xorg freezes in the lock screen + Screen freezes in the lock screen ** Tags added: amdgpu -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xorg in Ubuntu. https://bugs.launchpad.net/bugs/1939013 Title: Screen freezes in the lock screen To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+bug/1939013/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp