Unfortunately an inactive monitor that is connected is usually still detected as a monitor. So the system can only try to do the right thing and try to use it.
I agree with your suggestion that the live session and installation should use clone mode to cover this and other potential arrangement problems. So this is not a bug, but now an enhancement request. ** Package changed: xorg-server (Ubuntu) => gnome-shell (Ubuntu) ** Changed in: gnome-shell (Ubuntu) Status: Incomplete => New ** Changed in: gnome-shell (Ubuntu) Importance: Undecided => Wishlist ** Summary changed: - install starts with 2 screens. insteadl of 1 + With multiple monitors, live sessions and the installer should use clone mode, not spanning. ** Tags added: multimonitor -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to gnome-shell in Ubuntu. https://bugs.launchpad.net/bugs/1778093 Title: With multiple monitors, live sessions and the installer should use clone mode, not spanning. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-shell/+bug/1778093/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs