Found a workaround: xrandr --addmode HDMI-1-2 1920x1080 xrandr --output HDMI-1-2 --mode 1920x1080
This sequence of commands enables clone display. However, I still don't see anywhere in Displays/Monitors the secondary display. Here is the xrandr output (while projector is on): HDMI-1-1 disconnected 1920x1080+0+0 (normal left inverted right x axis y axis) 0mm x 0mm 1920x1080 60.02* -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to libxrandr in Ubuntu. https://bugs.launchpad.net/bugs/1771185 Title: Secondary monitor not connecting in 18.04 LTS To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/libxrandr/+bug/1771185/+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