Night Light is not functioning

[Jeb E.]

Night Light is not shading/filtering the screen anymore after the update to Cosmic (Ubuntu 18.10) from Bionic (Ubuntu 18.04 LTS).
It still appears as an option and all the settings work, but the feature itself isn't filtering out blue light from the screen.

ProblemType: Bug
DistroRelease: Ubuntu 18.10
Package: gnome-control-center 1:3.30.1-1ubuntu2
ProcVersionSignature: Ubuntu 4.18.0-10.11-generic 4.18.12
Uname: Linux 4.18.0-10-generic x86_64
ApportVersion: 2.20.10-0ubuntu13
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Fri Oct 19 11:03:28 2018
InstallationDate: Installed on 2018-08-17 (63 days ago)
InstallationMedia: Ubuntu 18.04 LTS "Bionic Beaver" - Release amd64 (20180426)
ProcEnviron:
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: gnome-control-center
UpgradeStatus: Upgraded to cosmic on 2018-10-19 (0 days ago)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Sebastien Bacher (seb128)]

Thank you for your bug report. Could you add your journalctl log after enabling the feature?

[Launchpad Janitor (janitor)]

[Expired for gnome-control-center (Ubuntu) because there has been no activity for 60 days.]

[MegaBrutal (qbu6to)]

Night light stopped working for me from Disco to Eoan upgrade.

[MegaBrutal (qbu6to)]

Now I found out that it depends on whether I login with Xorg or Wayland.
Night Light works with Xorg, but doesn't with Wayland.
I honestly don't remember whether I was running Disco with Xorg or Wayland, most probably I just went with the default. My guess is that Disco used Xorg by default and Eoan changed to Wayland, that's why I thought it's broken with the upgrade.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Timo Aaltonen (tjaalton)]

still doesn't make it a wayland bug

[Vladimir Kondratyev (vladimirkondratyev)]

I confirm that on my Dell XPS 13 night light does not work in Waylay session. All is OK in with XOrg. I'm using Ubuntu 19.10, new installation.

[Sebastien Bacher (seb128)]

the 19.10/wayland issue is new and tracked as bug ##1847551, that old ticket is another issue

[MegaBrutal (qbu6to)]

Guys, with today's reboot Night Light works with Wayland. Now I see a fix for Mutter has been released for #1847551 that I installed on Nov 21 but didn't reboot until today. Indeed it was not an issue with Wayland, sorry for reporting it as such.

[Dan Dascalescu (ddascalescu+launchpad)]

Nightlight just stopped working on my ThinkPad X1C 7th gen with Ubuntu 18.04.4 too after the last updates. But on the other hand, the trackpad is now working again, yay. :-/

[Daniel van Vugt (vanvugt)]

This bug closed automatically because the original reporter did not respond. Please open a new bug by running:

  ubuntu-bug gnome-shell