Guide 9 wants to use non-existent "second monitor"

Ted Blank Apr 10, 2018

I have a second monitor on my laptop, connected via a USB docking station.  Before taking the laptop on a trip, and before disconnecting the second monitor, I change the Windows 10 setting to make the laptop the primary display.  Then I disconnect the extra monitor.

Even after I re-boot the laptop, when bring up Guide, right-click on a star and select "More Info", Guide 9 somehow remembers the old configuration and puts the "more info" pop-up onto the (now non-existent) second monitor - thus it is invisible.  At that point all I can do is hit the Esc key to bring control back to the main screen, but I never see the "more info" pop-up.

Does anyone have any idea how to tell Guide that there is no longer a second monitor available?  Is this a windows 10 bug?  It must be something Guide is remembering, since this behavior survives even a complete power-off reboot.