Headphone selection is resetting in Cubase

I want to listen to my mix on headphones when I use Cubase but it is not working.
Before I start Cubase I select headphones on out 1/2 and when I listen to a song
on mediaplayer its working. As soon as I start Cubase and want to listen I don’t hear
When I shut down Cubase and check the editor it changed the headphone output
automatically to output 7/8. Can anybody give me a solution for this problem, it’s
driving me nuts.

Best regards,