Actually the attached monitors.xml.txt suggests the system doesn't have any saved configurations for using the laptop screen only. It looks like it only has known configurations that disable the laptop screen.
That sounds like a bug, and to fix it I can only recommend: 1. Delete ~/.config/monitors.xml 2. Reboot. 3. Unplug all external monitors. 4. Go to Settings and change some display settings. 5. Log out and in again. 6. Verify ~/.config/monitors.xml exists now. 7. Plug your external monitor in and configure it again in Settings. ** Package changed: gnome-shell (Ubuntu) => mutter (Ubuntu) ** Tags added: hotplug multimonitor -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2060384 Title: I'm using an external diplay. When disconnecting the HDMI cable, my laptop screen remains dark (when it should actually activate)+ To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/mutter/+bug/2060384/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
