@support -
Glad this thread got reactivated.
I’ve been testing out my new iFi Pro iDSD DAC and ran into a similar problem, which I disgustedly reported to iFI. Now, it seems as though it might be a Roon problem.
I know the OP uses ROCK, but I run Roon under Windows 10. I don’t use DSP, but the DAC upsamples to 702K. The other day I couldn’t decide what I wanted to listen to, which resulted me switching from a track recorded in aac to one in flac and back again.
Doing so caused the DAC to drop its USB connectivity. My SMS-200 could no longer discover it. Turning the DAC off/on resolved the problem.
Does this sound like the same thing?