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.
** Also affects: wayland (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to wayland in Ubuntu. https://bugs.launchpad.net/bugs/1798840 Title: Night Light is not functioning To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-control-center/+bug/1798840/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp