IMac, Roon and Schiit Modi not linking as expected

Roon ROCK - Intel Nuc 10iFNHNI7, 128 GB

iMac into a Schiit Modi M via USB, RCA out of the Modi into a Schiit Freya plus.

140,000 tracks

Roon working great everywhere around the house. I have my desktop iMac connected as above into my office hifi system. When I select System Output or Modi Multibit as outputs, I get sound. When I select USB Schiit Modi (with the cute little icon that looks like the Modi), I get silence even though I can see track playing at the bottom of the window.
Given that the Modi has the icon, intuitively it seems the output to select rather than the other two mentioned above. Am I missing something?

Hey @Stuart_Edwards1,

Thanks for taking the time to write in! It’s great to see you in the community again. Following up on your thread, I wanted to see if you’re still running into audio playback issues with your Schiit Modi M?

A quick question - does the light turn on on the Modi M to confirm you have the USB source selected?

And to confirm, For USB, have you selected the Modi as the audio output device in Control Panel (Windows) or System Preferences (Mac) AND in Roon? I would also triple-check that the Modi M is configured to use USB instead of SPDIF or other means of audio playback. With that, try a different USB cable or USB port to ensure you don’t have a faulty cord or USB port.

I’ll be on standby for your reply :pray: