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*
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*