Sorry, I misread the dates. There was also a 'mutter' update at the end of April, so that may be the problem. To confirm this, please try reinstalling the .deb files of the prior version:
https://launchpad.net/ubuntu/+source/mutter/3.28.3+git20190124-0ubuntu18.04.1/+build/16422451 and then reboot. ** Package changed: xorg-server (Ubuntu) => mutter (Ubuntu) ** Changed in: mutter (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1828665 Title: [regression] Reboot after dpkg update set invalid Graphics resolutions (Dual Monitor) since ~7th/8th May To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1828665/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs