I'm attaching the complete list of packages upgraded on the second laptop that triggered this bug.
The total list is over 300 packages. I've prefixed the unlikely package with #. That leaves 77 possibles all related to X server or display drivers. ** Attachment added: "List of upgraded packages with unlikely's prefixed #" https://bugs.launchpad.net/ubuntu/+source/libxcb/+bug/1873895/+attachment/5357163/+files/upgrade.list -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to libxcb in Ubuntu. https://bugs.launchpad.net/bugs/1873895 Title: Regression: block staircase display with side-by-side monitors To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/libxcb/+bug/1873895/+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