Welcome, @Maximilian_Laske !
Check this thread that I started more than three years ago. Never really found a solution since, and it’s still occuring one time on three, on my end… 
So, if as me, the main symptoms on your end are, both, no sound and no activity in the Audio performance meter, there is more or less a workaround : use the Reset button placed at the bottom of the Studio > Studio Setup > Audio System panel. Sometimes you’ll have to do so twice or even more to wake up your whole setup…