Questions[night-light](ubuntu)

Today I realized that Night Light stopped working in my machine. When I try to set it up, nothing happens. See attached gif:

I am not sure what's causing it to fail. I don't know if there are any logs generated by this tool, or if there's another way to enable Night Light.

Any idea what to try? This was working a few months ago.

When I check /var/log/syslog, there are some messages related to night light when I use the «Sunset to Sunrise» schedule, but nothing indicates that it failed:

Sep 19 22:46:37 sambayon gnome-control-c[22940]: no sunset data, using 16.00
Sep 19 22:46:37 sambayon gnome-control-c[22940]: no sunrise data, using 8.00

I have a 2019 Dell XPS 13 2-in-1 7390 connected to Dell D6000 docking station and using Dell SE2719HR secondary monitor. The dock uses DisplayLink technology, for all it matters. My Ubuntu version is 20.04.

When I enable Night Light, it is only displayed on the laptop's built-in monitor. Even when I close the lid (which turns off the built-in monitor), Night Light still isn't displayed in the external monitor.

I've tried mirroring displays, extending displays, setting external display as only one active, nothing helped. I went through this topic here and all suggested solutions, none helped either.

Is this a bug of some sort, or am I doing something wrong?

How to set automatic night mode in Ubuntu 20.04?

In Ubuntu 19.04 options I have to set the time automatic night mode on.

The Night Light filter, also known as Blue Light filter or Color Temperature filter, is a bit hard to find in Ubuntu 20.04. The Night Light tab is now in shown in the title bar, next to the Displays tab. These 2 tab labels look like they are just a title, but in fact they can be clicked on. (BTW it's Settings -> Devices -> Displays: Night Light in Ubuntu 18.04.)

I'm running 18.04. I have the night light set to run from sunset to sunrise. However, it's been turning on early, multiple hours before sunset and is already to maximum redness before the sun even starts setting. Perhaps it's a bug that mishandles the daylight savings time shift? I don't think it used to be this bad before the time change. (I'm on PDT.) I've checked the time settings, it's all correct.

Anyone run into a similar issue? Any fixes (aside from just manually setting the night light times myself)?