I just looked at my connector and there's nothing surrounding the center pin, except a few cobwebs that I cleaned out. I'm able to see down to where the pin mounts into the plastic, which is flat and shiny.
Take a look at the truck side of the the connector. You might be able to gently squeeze the middle pin contact tabs together a bit to tighten up the fit of the connector.
I looked closely at your pictures, and to me it looks like plastic shavings from the plug itself surrounding the middle pin- maybe a minor manufacturing defect. It wouldn't hurt anything to take a small nail and try to pry or scrape it out. Doing that might allow you to seat the plug more deeply into the receptacle. The center pin is just molded into the plastic plug, so there wouldn't be anything that could be damaged by giving that a try.
2011 Dodge Ram 1500 HEMI Quad Cab
2011 Jay Flight 26BH