So I’ve seen this a few times now. It’s definitely only an issue with Roon, not say iTunes.
Basically, I have my 16MacBookPro running the roon app (core is on a linux box) and I have two ways of sending data to my Bifrost2: USB (CoreAudio) or to a HiFiBerry->Coax. (Don’t ask why, it’s complicated, but basically my laptop isn’t always connected to the Bifrost over USB.)
I have both USB and HiFiBerry zones grouped together, so I only have to switch inputs on the Bifrost2.
What I notice though is the USB zone tends to randomly not work. When that is happening, if I head over to Settings -> Audio there’s a pretty good chance Roon will crash. But generally it seems confused about the Bifrost USB device. At one point it seems to have detected the Bifrost a 2nd time and I had two USB devices listed because it got confused. Although I’ve now deleted the redundant entry.
Any tricks to keeping Roon happy? Sadly, “don’t disconnect the USB” or “always use the HiFiBerry” really aren’t viable options for me and frankly this one of the features that brought me to Roon.
Both Core & Mac are running Roon 1.7 build 610.