My trigger pin did the same thing on my first trip to the range after installation of the Apex spring kit. I didnt even notice it until I got home and went to put it away in the safe. I pushed it back in to where it was and noticed that it was flush on the left side, but pushed in a small amount from the right... so I gave it a little tiny push in from left to right and heard a little "click". Now both sides look equal.... and after 100 rounds this past weekend, it did not move at all.
I know you didnt do the Apex install or anything, but it makes me wonder if maybe the factory didnt set the pin all the way in like its supposed to be. Not sure if my post will help at all, but you may need to just try to give it a little tap from left to right and listen for a click!