There's a slight chance this is a side-effect of gnome-settings-daemon trying to enforce the default colour profile. It's a bit of a mess but I believe that does so by programming the display hardware directly, independently of the power mode mutter/gnome-shell last set. So if gnome-settings-daemon has touched the hardware more recently than mutter /gnome-shell I imagine problems like this might occur.
To reduce or eliminate the risk of that you can disable (toggle off) the default profile for your display(s) in: Settings > Color -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to gnome-shell in Ubuntu. https://bugs.launchpad.net/bugs/1882462 Title: Displays wake up pre-maturely (likely driven by notification) Status in gnome-shell package in Ubuntu: Confirmed Bug description: After a period of time, my displays go to sleep as they should. However, I often come back to find that the displays are awake, the mouse pointer is on a screen, but the screens are otherwise black. They're in this weird "awake but not fully on" mode. At that point, they will not go back to sleep as they should unless I fully awake them and let them go back to sleep. I don't know exactly what triggers the "half awake" but I suspect it's a notification. The displays shouldn't turn on without a user action. It wastes power and is clearly broken. I've attached a photo for an example. ProblemType: Bug DistroRelease: Ubuntu 20.04 Package: gnome-shell 3.36.2-1ubuntu1~20.04.1 ProcVersionSignature: Ubuntu 5.4.0-33.37-generic 5.4.34 Uname: Linux 5.4.0-33-generic x86_64 NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair ApportVersion: 2.20.11-0ubuntu27.2 Architecture: amd64 CasperMD5CheckResult: skip CurrentDesktop: ubuntu:GNOME Date: Sun Jun 7 16:10:20 2020 DisplayManager: gdm3 InstallationDate: Installed on 2018-07-24 (684 days ago) InstallationMedia: Ubuntu 18.04.1 LTS "Bionic Beaver" - Release amd64 (20180724) ProcEnviron: TERM=xterm PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=en_US.UTF-8 SHELL=/bin/bash RelatedPackageVersions: mutter-common 3.36.2-1ubuntu1~20.04.1 SourcePackage: gnome-shell UpgradeStatus: Upgraded to focal on 2020-01-07 (152 days ago) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-shell/+bug/1882462/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
