High-Impedance Headphones

Hey. I just grabbed this software and still working it out.
I’m running Audulus on an M2 MacBook Air and can build a basic module synth to make a tone that plays through both my Mac speakers and external monitors with an external soundcard.

However, When I plug in high-impedence headphones (Beyerdynamic DT 770’s), no sound.
The mac is designed to work with high-impedence headphones and they work with music and streaming just fine.
The Audulus software also works fine with my AirPods Pro.

Is it the software that doesn’t support the headphones? Or is there a node I’m missing?
Any help or advice would be nova!