I have an issue with xrandr and my dual screen setup. This happend suddenly after a reboot, so there are no (intentionally) changed settings. Here is what happened:
My external monitor stands left to my laptop, but suddenly my system behaves as the monitor is on the right side. I went into the monitor prefs dialog of the Mate desktop and moved the screen accordingly. I noted the miniature created a trace as i dragged it. After I applied the change, the displays switched as expected, but I cannot click on the display it triggers clicks on the other screen. So the dialog "Keep changes ..." is on the internal monitor but I have to click the corresponding location on the external screen. The visible pointer is on the external screen, but an "invisible" pointer is on the internal screen raising the click events.
This is the output of
Screen 0: minimum 320 x 200, current 3840 x 1080, maximum 16384 x 16384 LVDS-1 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 344mm x 193mm 1920x1080 60.02*+ 50.03 1680x1050 60.00 1400x1050 60.00 1280x1024 59.95 1280x960 59.99 1152x864 59.97 1024x768 59.95 800x600 59.96 640x480 59.94 720x400 59.97 640x400 59.96 640x350 59.84 VGA-1 connected 1920x1080+1920+0 (normal left inverted right x axis y axis) 476mm x 268mm 1920x1080 60.00*+ 1680x1050 59.95 1280x1024 60.02 1440x900 59.89 1280x720 60.00 1024x768 60.00 800x600 60.32 640x480 59.94 720x400 70.08 DP-1 disconnected (normal left inverted right x axis y axis) DP-2 disconnected (normal left inverted right x axis y axis) DP-3 disconnected (normal left inverted right x axis y axis)
I never had to debug issues with graphics so please ask for more information if required.