If you're talking about "Dim Screen When Inactive", that option should only appear on laptops with backlights.
So I think the only problem here is that gnome-control-center is showing the option at all. It's not expected to work on desktops and/or external monitors. ** Package changed: xorg (Ubuntu) => gnome-control-center (Ubuntu) ** Also affects: mutter (Ubuntu) Importance: Undecided Status: New ** Changed in: gnome-control-center (Ubuntu) Status: New => Won't Fix ** No longer affects: mutter (Ubuntu) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1875639 Title: Settings/energy/screen saver ... it doesn't work. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-control-center/+bug/1875639/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs