No, you understood fine.
With Win11, Roon works fine with the dac(s) connected via USB.
But we cannot figure out what’s the issue with the combination of Audiolinux - Roon - USB connected dac s and this minicomputer.
But this case can be closed, I will use this PC for something else and move to the old laptop of my wife with broken display. Pretty confident that will work fine.
Thanks for the follow-up and support. Dirk