mini monitor audio with Avid Media Compser

I've just installed the UltraStudio mini monitor on my Avid Media Composer (Mac OS 10.13.5) and the picture works great giving me a full screen 3rd monitor. The problem is that even though I have the Mac set for the audio to continue through my ONYX Blackjack USB audio I/O device, it instead goes through the mini monitor HDMI to the 3rd monitor and I get no sound to my external speakers. How can I insure that only picture goes through the mini monitor and not audio? I need audio to go through the external mixer to my speakers as set in my Mac's sound preferences. Thanks for any help you can offer!

Same question here on Windows10 & Media Composer 2018.x.

Previously I had a Matrox MXO2 I/O device, and when clicking on Media Composer's Audio Monitor Control, I could choose between the Matrox box or the Windows default audio device for audio playback with client monitor. At that time I didn't realize it was a Matrox feature, not a Media Composer feature. So I was surprised when I discovered that this option was absent using the BMD UltraStudio Mini Monitor.

Would it be possible for BMD to update the UltraStudio software for Media Composer so that the user can choose between the Windows default audio device or the BMD UltraStudio device for audio playback ?

Reviving this topic:

How can I monitor Media Composer with Mini Monitor with:
1) picture (only) to a HDMI (or SDI) display device
2) audio to a separate audio device (SPDIF or USB)

Any suggestions appreciated