Opening panel now going behind black screen

[Aussie1234]

I have a three screen View group set up (L,C,R). It transferred OK from v4.2 to v4.3. (Client and Content upgrade)

The problem I have is on start-up, If I click 'OK' to my default Scenario, on the first panel, or change the time, weather, and click OK, everything proceeds well and the views come up as usual in its own time.

However, If I select a new airport and click OK, the screen goes black and sits there. Took me a long time to figure out the first panel is now located behind the black screen. Accessible only from the Task Bar and very inconvenient.

Is there a way to get it to revert to sitting on top of the external view, as before, after selecting a new airport?
Aussie.