Cubase 10.5 doesn't work anymore after I change window

Hello everyone !
I use cubase 10.5 as an amateur and a music teacher. And since the beginning I have the same problem. When I want to use another program (chrome, word) or juste minimize the window to search something on the desktop while using cubase, cubase blocks ans I have to force closing the program and reopen again.
How do you think I can solve this problem ? Is there a possible conflict with my windows 10 ?
Thank you !