Cubase 8.0.20 appears background

Hello, with Cubase 8.0.20 I have a problem while import track and after save project. Almost every time pops up what I have in the background (eg Total Commander or RME mixer, etc.). Can you do something about it? It is very annoying bug. It’s weird because I’ve never had such problems (I use Cubase since 1996)

The same problem of disappearing cubase “grey area” background when the project is closed and next selecting eg Total Commander from windows 7 taskbar. “Grey area” becomes transparent and I can not drag & drop cpr files from Total Commander to Cubase (like always in old Cubase 6.5)

greetings
Adam

Windows 7, Cubase 64-bit, Only one monitor