Unreal Engine Livestream - Building a Music System in Blueprints - Apr 5 - Live from Epic HQ

That’s really strange, you say they worked once but then not again?

Are you sure you’re on the New Audio Engine?

We have a sticky on how to get it set up on Mac:
https://forums.unrealengine.com/development-discussion/audio/116874-new-audio-engine-early-access-quick-start-guide

I admit to never having tested this on Mac, but I did build the system originally for a middle-to-high-end mobile device, so I would expect it to work generally okay on Desktop platforms.