Ubuntu – After upgrading to ubuntu 20.04 Lockscreen not working

20.04lock-screen

I tried the shortcut Super + L nothing happens.

In the settings, have set lockdown timer for 1 min, nothings happens after that.

In the right corner menu after clicking lock item, it is showing black screen and logging me out.

gsettings get org.gnome.desktop.lockdown disable-lock-screen

shows false.

Best Answer

  • I was having EXACTLY the same problem. It turns out I have several display managers installed, and I was using lightdm instead of gdm3.

    You can confirm you are using lightdm if this command works:

    $ dm-tool lock
    

    (But even if that doesn't work you may be using another display manager.)

    I got the screen blanking to work properly by configuring gdm3.

    Open a terminal and issue this command:

    $ sudo dpkg-reconfigure gdm3
    

    Select gdm3 in the list on the terminal, then reboot your system.