No audio out from Main Out L/R

I am getting audio from headphones and only through USB. I have Main Out L/R going into a Focusrite audio interface, hoping to record different external synths in Logic Pro using the Focusrite as Core-Audio and not Elektron Samples (incidentally, this is the only way I seem to be able to get any audio input from ES into Logic by selecting it as input and via USB) - what am I possibly missing here or doing wrong?

Thanks for your input! (or no input as it stands)

The INT OUT is set to ON