Strange one:
macOS 10.13.6 (High Sierra)
RME Babyface Pro firmware 2.00, driver 3.222

Evercast's desktop application will not stream audio out the RME Babyface. It will stream out of the system's built-in output and Pro Tools HDX, but the Babyface Pro will not output. Totalmix shows no input being received from the application either (though the test tones in Evercast do work.) If I try to aggregate the Babyface Pro with the System Output, that aggregate device won't work until I remove the Babyface Pro (even if it isn't the channels set to play the stereo out.) Explicitly pointing to the Babyface Pro in Evercast doesn't work nor does setting the Babyface Pro as the default audio device for the system and then setting Evercast to use the default system out.
But, always, the speaker test in Evercast does work (going out the Babyface Pro.)

This is really confounding me what could be mismatched here. I upgraded the Babyface Pro to the latest firmware and driver hoping that'd fix it but didn't. I've tried the short offset checkbox, that didn't work. The Babyface Pro (and every other device in the system) is set to 48k (which matches the incoming stream.)

Any ideas?
(The application is the free desktop mac Evercast application v2.1.4 -- latest version. It's used for remote collaboration for post production audio)