I called S&W about the issue of the first round sticking up when loading a magazine with force, during slidelock, in an M&P22 and they gave me a fix that works:
Slightly pinch the feed lips at the front of where they grip the round only (I used a small vise grip). After pinching the mag, S&W say to use dummy rounds, but I don't have any and with the safety on and aimed in a safe direction, tested it. If you go too far, they won't load, but just enough and the top round doesn't pop up anymore. I have eight mags and they all now load perfectly with a hard insertion.