I just had EXACTLY the same thing happen to me on my 2017 Grand Sport C.E.!!! I started having a slow leak so I took it to my local tire store and they said the wheel had a small crack.

At their recommendation I took my car to the dealer since I only had 20,000 miles. They submitted it and it came back almost immediately from GM rejected! Same exact crap! Said "there was a small scratch therefore I must have hit a large pothole or something". No damn scratch and I have NOT hit anything ... I'm VERY careful with my "baby"!

I had the wheel repaired (welded and balanced) at a local wheel shop.

I just saw an article where there is a pending class action lawsuit against GM for these defective wheels. Anyone know how to get included in this action?