xfce4-display-settings randomly blocks overlaying ('same-as') mode

Submitted by John

Assigned to Jérôme Guelfucci

Link to original bug (#12570)

Description

I frequently take my notebook to the universities where I teach. Each has different projectors, and at home I don't have any, so I find myself frequently switching configurations.

Lately, and randomly, the display-settings comes up convinced that the laptop's and projector's screens are not overlayable. I.e. when trying to move one display on top of the other, display-settings doesn't let me. (the images representing move around one another, but never on top of each other). I am not sure I'm doing it right - except sometimes it does work as expected.

Somewhat ignorant about what criteria display-settings used to permit overlay, I checked the frame rates - there is a small difference (60.3 vs 60.0 Hz). Could that be the reason?

xrandr --output LCDS --same-as VGA-0 worked instantly though.

Is there anything else I need to be aware of?

Version: 4.12.0