Rekordbox doesn't recognize audio when the OPUS QUAD isn't the audio source

Hi, new user of OPUS QUAD here.  I have a Mac Studio with a MOTU 8D as an external sound card.  Whenever I use Serato I have no issue selecting the 8D as an audio source (via the Use Laptop Speakers setting in preferenes) and everything works fine.

When I go to use rekordbox, however, and I select 8D as the audio source and have the Mixer in either Internal or External mode the audio will play through if I raise the fader, but the OPUS / rekorxbox doesn't recognize the Mixer... e.g. the meters don't light up, and the EQs don't affect the sound.  Can anyone please help me setup rekordbox correctly to use my 8D as the audio card (i.e bypass the OPUS' sound card) but use the OPUS QUAD as the mixer/controller?

Thanks!

-Keith

PS.  I have screenshots if there is a way to upload those???