Gnome Night Light Stuck As Enabled If Monitor Is Turned Off
Affected version
Linux 6.8.5-301.fc40.x86_64
Fedora Linux 40.20240416.n.0 (Silverblue)
Gnome 46
Wayland
Happens even without extensions. (Session was restarted with all non-built-in extensions disabled.)
Bug summary
If Gnome 3's Night Light is enabled and running when a monitor is disabled in the settings, then that monitor's color temperature will be stuck at the Night Light temp when it's re-enabled, regardless if Night Light is actually running, or if any other monitors are red shifted.
Background: I have two monitors hooked up, and when I lock my screen, they both turn off and back on at different rates until they either both stay off, or both stay on. This is an unrelated bug. But due this this bug, I go into my settings to turn off one monitor before locking my computer and going to sleep.
However, when I turn that monitor back on the next morning, its color temperature is still stuck at the temperature Night Light set it so before the monitor was disabled. This happens even if the other monitor is showing a normal unmodified color temperature.
I assume it's because Night Light doesn't keep track of each monitor and it's normal color temp, or maybe Night Light doesn't adjust the color for monitors newly plugged in/enabled during the day.
Going into the Night Light settings and adjusting the slider forces a preview mode, when will correct the color temperature on all monitors after the color temp preview ends.
Steps to reproduce
- Turn on Gnome Shell's Night Light.
- Wait for the monitor color temps to shift, or manually set it to always enabled with the schedule.
- Disable one monitor in the Displays settings page, but leave another enabled.
- Wait for the monitor color temps to return to normal, or disable Night Light.
- Re-enable the monitor that was disabled.
What happened
Re-enabled monitors show the incorrect, previously set, color temperature.
What did you expect to happen
Re-enabled monitors should be set to the current Night Light global color temperature. If Night Light is disabled, or not currently adding red, the re-enabled monitor should be re-enabled with it's normal color temp.