1. xrandr I generated the output and attached the section for the external display. I guess the first line already shows the problem:
HDMI-1 connected 1920x1080+1366+0 (0x8b) normal (normal left inverted right x axis y axis) 160mm x 90mm It includes "160mm x 90mm" which probably translates to 7". 2. apport I generated the requested log. I installed Ubuntu 17.04, upgraded to 17.10 and now upgraded to 18.04. I use the latest kernel from kernel.ubuntu.com. ** Attachment added: "xrandr output for external display" https://bugs.launchpad.net/ubuntu/+source/mutter/+bug/1792167/+attachment/5188367/+files/xrandr.log -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to mutter in Ubuntu. https://bugs.launchpad.net/bugs/1792167 Title: Display size detected incorrectly To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/mutter/+bug/1792167/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs