there is maybe a papers width between the bushing turned all the way left and the plug. So when the plug slides out it slides against the bushing leaving small polished (scratches) where they touch.
Sure by taking it down a better way, using the slide stop first and then the whole bb/slide assembly. Good youtube videos showing how.
I tried that method for the first time a few days ago, and when I got the slide off of the frame, the recoil spring bowed outward like a cat arching its back and I thought it was going to fly out at me. The bend wasn't enough to permanently deform the spring, but it didn't look healthy. I'll try to find some of the videos to see if I was doing something wrong.
This is much ado about nothing. It happens to all of them. It is not a defect or problem with your gun.