Cubase Pro 11 + GuitarRig 6 - Insert cancels audio?

I have an odd issue with GR6 and Cubase. I set up an Audio track and can monitor the sound input of my guitar fine. However if I then insert GR6 as an effect it cancels out my audio completely.

If I bypass the effect I can hear the audio track fine?

I can insert any other effect and hear the audio played back with the effect with no issues, only GR6 causes the issue.

I can use GR6 in standalone mode without any issues, just not as an insert. Anyone got any ideas if I am missing something?