Just FYI if it can help you guys in any way (I do know this is an Ubuntu forum), I'm adding a confirmation that this is not Ubuntu specific. I've also reproduced it in Fedora 27 under Wayland with 3 monitors: left horizontal, middle vertical (rotated right), right horizontal. There's algo an open bug in Fedora Bugzilla: see RedHat bug: https://bugzilla.redhat.com/show_bug.cgi?id=1513160.
Just FYI if it can help you guys in any way (I do know this is an Ubuntu forum), I'm adding a confirmation that this is not Ubuntu specific. I've also reproduced it in Fedora 27 under Wayland with 3 monitors: left horizontal, middle vertical (rotated right), right horizontal. There's algo an open bug in Fedora Bugzilla: see RedHat bug: https:/ /bugzilla. redhat. com/show_ bug.cgi? id=1513160.