I wonder if this is caused by uncoordinated KMS updates not relating to displaying the primary plane. I imagine some of those will wake the monitor up even though there's no image to display. And even worse; some of them will come from gnome-settings-daemon beyond the control of gnome-shell/mutter (which is fixed in GNOME 43). To mitigate this, please try disabling features that might cause such updates:
* Settings > Colour > turn OFF for all screens * Settings > Screen Display > Night Light = OFF * Software-controlled privacy screens on some models of laptop -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to mutter in Ubuntu. https://bugs.launchpad.net/bugs/1973467 Title: [Wayland] Backlight stays on with black screen when monitor should be sleeping To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/mutter/+bug/1973467/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
