Prophet 08 and logic not talking properly and playing on wrong track

I've had some problems suddenly arise with my Prophet 08 and Logic for some reason

I've had it set up as an external instrument and running successfully for a few years now but last week it just stopped responding to midi coming back from the sequencer.

I'm not sure if I've moved something or a setting has got changed but I am able to see a signal going into to logic, and can record notes as expected.

They even register on the Prophet when they play back but no sound comes out.

However, when I move to the adjacent track in logic which is set to a software instrument, I can hear the Prophet coming through perfectly but not the software instrument??

Midi is going into Logic via a Kenton thru box into a saffire 56

Midi is coming back to the Prophet via Maschine studio which is connected via USB to my mac.

Maschine is also sending midi (via the Prophet) to a DX7 and that is able to send and receive as expected.

So something is happening to the Prophet in the middle and I just can't figure it out...

Any clues appreciated!!