Back Plate Scuffs?

I was cleaning my m&p9 after a very great time at the range. I noticed that there was a some plastic that was damaged on the rear plate. I know this may seem knit picky. I have multiple M&Ps, they all have little scuffs, but this one is more scuffed up than the other M&Ps even though it has fewer rounds.

Almost looks like the firing pin stop is a little low in your right picture, perhaps not perfectly fitted? I would not worry about it. If it really bothers you, contact S&W.