Quick update. I do not have tlp installed and it also does it on Wayland.
I'm out of ideas.

On Wed, Jun 24, 2020 at 9:25 PM Daniel van Vugt <email address hidden>
wrote:

> Another idea: You seem to be using the default Xorg session so that
> increases the possible set of components that could tamper with the
> power state. Please try logging into 'Ubuntu on Wayland' to see if the
> problem happens there.
>
> And another idea: Check that you don't have 'tlp' installed. It causes
> random power management bugs. Assuming the issue is not tlp, please also
> report it upstream at: https://gitlab.gnome.org/GNOME/mutter/issues
>
> If you are feeling adventurous then it might help to figure out the
> exact time of day the display is waking. Like with a timelapse video
> next to a clock that's synchronized to the machine's clock. That could
> then be compared to the system log or might spark other ideas.
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> 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
>
> Launchpad-Notification-Type: bug
> Launchpad-Bug: distribution=ubuntu; sourcepackage=gnome-shell;
> component=main; status=Confirmed; importance=Undecided; assignee=None;
> Launchpad-Bug-Tags: amd64 apport-bug focal
> Launchpad-Bug-Information-Type: Public
> Launchpad-Bug-Private: no
> Launchpad-Bug-Security-Vulnerability: no
> Launchpad-Bug-Commenters: dean seb128 vanvugt
> Launchpad-Bug-Reporter: Dean Henrichsmeyer (dean)
> Launchpad-Bug-Modifier: Daniel van Vugt (vanvugt)
> Launchpad-Message-Rationale: Subscriber
> Launchpad-Message-For: dean
>