Looks like this bug only affects Wayland sessions. So to avoid it just log into "Ubuntu" instead, to get Xorg.
** Summary changed: - Mutter 3.34.1 broke Night Light, screen color profiles + Mutter 3.34.1 broke Night Light, screen color profiles in Xorg sessions ** Summary changed: - Mutter 3.34.1 broke Night Light, screen color profiles in Xorg sessions + Mutter 3.34.1 broke Night Light, screen color profiles in Wayland sessions -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to mutter in Ubuntu. https://bugs.launchpad.net/bugs/1847551 Title: Mutter 3.34.1 broke Night Light, screen color profiles in Wayland sessions Status in Mutter: Fix Released Status in mutter package in Ubuntu: Triaged Bug description: Upgrading Mutter 3.34.0 to 3.34.1 has broken Night Light and screen color profile switching. The commit at fault is 104bdde746c9ceccd9e9ab09b22ef228b8f7026e “kms: Predict state changes when processing update” (which was intended to fix LP bug 1847044). Upstream issue: https://gitlab.gnome.org/GNOME/mutter/issues/851 To manage notifications about this bug go to: https://bugs.launchpad.net/mutter/+bug/1847551/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp

