Could it be the airbox? Tire cupping? Another thing to check might be chain tension. Mine was way too tight when I got my AT (used) and I think it may have contributed to a low pitched whining I would notice at low speed.
My starter motor was staying engaged - amazingly I drove several thousand miles with this happening before one day driving without my earplugs and hearing the whining. Says a lot for the reliability of the At’s starter motor if it can be driven at high revs for so long without seizing
The AT chain has to be adjusted with the bike on the side stand. The weight of the machine compresses the suspension and tightens the chain. When I got mine the tech had adjusted it on the center stand. When I put it on the side stand the chain was bow string tight. This does not help your transmission output shaft bearing. The owner's manual clearly states that it should be done on the side stand.