Vortex Sound Research

I have my hardware synth sending audio to my interface. I have the midi out from my interface connected to midi in on my synth. Then I have my interface connected via USB to laptop and my midi keyboard also connected via USB to my laptop. I’m trying to use the external instrument plugin but I can’t get the keyboard to trigger the synth. My keyboard triggers my plugins etc so I know it’s working with live, and if I play the sequencer on the synth i hear it in live also. I just can’t get the keyboard to play the synth. Any tips?