It looks like the Nvidia driver also is not working for you... Try removing and reinstalling the Nvidia driver via the 'Additional Drivers' app.
Failing that, I think this should be merged into one of: bug 1880739, bug 1890957 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1901561 Title: night light not working To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+bug/1901561/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
