Welcome to the forum, Cheers!... 🍻
From the Owners manual:
NOTE: This motorcycle is equipped with interlock system for the ignition circuit and the starter circuit. The engine can only be started if: • The transmission is in neutral and the clutch is disengaged, or • The transmission is in gear, the side stand is fully up and the clutch is disengaged.

 

Welcome to the forum Don. It looks like thevili has got you covered on your question.

 

Thanks vili and Zoom for the welcome. What I don't understand is that until recently I have not had to pull in the clutch to start bike. Provided the bike was in neutral, key on press starter and bike fired first go every time. It could be this clutch switch may be on it's way out?

 

The clutch switch closes the ground circuit to the starter relay.
Without the clutch lever pulled, the starter relay would (should) not function.

The only portion of the ignition interlock that functions differently if you are in neutral compared to being in gear is the side-stand relay.

 

I thought I had the same issue one spring. I think I was just confusing my Yamaha with my Suzuki.
I seem to recall being told that you need to pull in the clutch to start all Suzukis.