Ubuntu
gnome-shell package

  1. Bug #1898153
  2. Comment #12

Comment 12 for bug 1898153

Revision history for this message
Rick T (ratulloch) wrote : Re: I upgraded from 18.04 to 20.04.1 and the screen doesn't lock or go blank at the set time.

I switched display managers from lightdm to gdm and it fixed the issue

sudo systemctl status display-manager

sudo dpkg-reconfigure lightdm

systemctl status gdm.service

sudo apt install --reinstall ubuntu-session

reboot machine

Info about the issue:
https://bbs.archlinux.org/viewtopic.php?id=150017

https://askubuntu.com/questions/1245071/cant-lock-screen-with-shortcut-on-ubuntu-20-04-gnome