This issue persisted two reboots and was immediately disappeared after upgrading gdm3 and switching to Wayland. So it only happens when using X.org.
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1970172 Title: External monitor switches to interlaced mode To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1970172/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs