Problems with dynamic multiple monitor setups in LM18.3, Mate

[lovecraft1024]

Hi,

A dynamic multi-monitor setup on my laptop is proving to be very difficult to work with.

Setup details: LM18.3 MATE on a Lenovo T470p. I plug into their "Ultra" dock which provides two DisplayPort outputs. I have two Dell U2515H monitors connected. All three screens are active in an extended desktop setup.

I manage to be able to get this setup eventually using the "Monitor Preferences" panel. This is fine as long as I stay connected to the dock. When I remove the laptop from the dock, the system won't reconfigure to a single display. This is manifest by the laptop screen showing only an empty desktop; the taskbar is on the (missing) monitor to the right. Even when the laptop display is selected as the main display, there are issues - windows that were on the external screens are still there, which seems to indicate that X or Mate hasn't reconfigured. Now, the best workaround is complete shutdown or reboot.

Strangely, at my home setup with a single Acer 2K display, the problem doesn't occur. I can plug in the monitor or remove it, directly from the machine's HDMI port and it works fine...

Any ideas for recovery, or even better, a solution, are appreciated!

CRW