I had same problem, found to be the rubber boot that goes round the throttle bodies/bottom of airfilter box. It was rubbing the right hand side butterfly link arms towards the front of the bike.
But only after alot of fiddling with the cable adjustment did i notice it.
Trim the underside of the rubber lip with a knife, I could see a very slight rub mark, the boot is shaped already to avoid this happening, but obviously it's a close tolerance and mine had somehow dropped half a mm or so ?
Let me know if this works, 5 minute job, probably going to be another 1125 quirk