I have upgraded from an Antipodes EX server to the new model S30, both are running AMS V3.0 and Roon 1.8 (build 814) software. When using the Ex I could use Roon DSP to convert from PCM to DSD however with the S30 I can upsample PCM but DSD does not show as an option on the menu (using the same Denafrips DAC and USB cable). I understand this may be because Roon does not identify the S30/Denafrips combo as being DSD compatible but I’m not sure why?
Roon queries the DAC to find out what it can do. If ithe device is not telling Roon it is DSD capable and it is, then there is something wrong. My initial guess would be that there might be a setting in the S30, since that is the equipment you changed. I am not familiar with the device. I would also suggest contacting Antipodes Audio and ask if there is something that needs to be set on the device in addition to discussing things with Roon support.
A screen shot(s) of the Audio Settings pages would also help to quickly see all the option that are set in Roon.