Drive wheel wearing down

So I bought a 40 tooth drive wheel pully, wanted to change my gear ratio for more torque. While installing it I noticed a strange wear pattern. There almost a 1/4 inch difference from side to side in the wheel, it being shorter on the inside (pully side) of the wheel. Any ideas?

do you see lines along inner side of the wheel? belt maybe rubbing.

put a white paper behind the wheel, should see a clear line (1mm is fine) between the belt and wheel.
turn the wheel, make sure it doesn’t move closer…

also I rotate my drive wheel ever few months, front to back and so on…

no belt rub, and the wear is incredibly even. Ill post a pic later. Was late getting to work today so trying to look really really busy :).