Window remains on 2nd monitor after it is unplugged

Hi.

Studio 2017, Win 10

My usual setup is a notebook with an external monitor where I usually work with Studio. When working on the road, I unplug the external monitor.

As of a couple of days, when I the external monitor, Studio insists on staying in the now unplugged monitor. I tried to reconfigure the monitors, to reboot etc., but Studio remains invisible: it is shown in the taskbar, but not visible on the now single monitor.

TIA

Best

g.