ROCK doesn’t have the Native DSD patch for this device yet (the patch is very new), but it will in the future.
We were able to reproduce this symptom on another Linux device that has the patch. The behavior is pretty nasty sounding. The device works fine in DoP mode. That is how I would recommend that you use it, at least until this is resolved.
Based on what we saw here, I don’t think there’s going to be a resolution to this in Linux or in Roon–it seems like the kind of issue that would have to be resolved in the DAC itself. The way Linux treats Native DSD DACs is very consistent from DAC to DAC, whereas on Windows, each DAC has its own driver. There are many XMOS-based DACs working on Linux, and have been for a while, so this seems like it should be technically surmountable.
We ran into a snag trying to get our Pre-Box S2 upgrade to the latest firmware, so our tests were conducted with 2.04. We’re going to follow up with Pro-Ject and see if that can be resolved in case this was fixed in the mean time.