Working with Cubase and youtube (ALL APPS) in the same time

Hello People,

i have a question.
I got Cubase 10.5, SSl 2+ as an Interface and Windows 10.
Everything worked fine, but since a couple of days i can’t hear anything else when Cubase is running.
It seems like cubase is using the driver all for himself.
So for example, i want to hear a song from YouTube and play guitar to it - it doesn’t work anymore.
I can hear the guitar, but no output from YouTube.

Do you have any Ideas?

Thank you!