I just got done posting in the 'failing differential' thread and saw this one. I have the same situation.
2019 GS, 75k miles, car lives outside and is washed approximately monthly via automatic car wash.
The pearl white paint is failing at the body seam line between the roof panel and the body side panels, above the doors.
I noticed that the paint had been touched up above the driver door several weeks after I bought the car in winter, 2022. (It was used / GM CPO.) This was annoying & frustrating to see, but since it was a used car, I decided to move on.
Last spring the touch-up paint began failing. Now all of the touch-up has cracked away and the original paint is failing and leaving a primer gray valley in the aforementioned body seam.
Once I determine what can/should be done about the noisy rear differential, I'll consider dealing with the failing paint.