No USB audio output on 2018 Mac mini

I’m trying to set up a 2018 Mac Mini with Roon (my old 2012 mini worked fine)
Installed Roon server, but can’t get audio out of the USB. I’m in exclusive mode and have checked the audio output on the mac to make sure it’s USB out, and nothing. I just hear the audio coming from the mac itself.

I take it you’ve enabled the System Output on your core Mac mini in Roon? Tried another USB cable?

Your device that is connected by USB has to be on for Roon to see it and then you need to enable that device in settings:audio.
And then you need to select that device as the target audio zone.