I am not sure if this will help, but I also shoot an M&P 9mm. When I first got it, mag changes were an issue and it took me a few seconds to get back on track. One of the more experienced shooters worked with me and saw that my grip was getting hosed because Iwas trying to reload low. He taught me a different way for mag changes, and after a lot of practice, it has helped a lot. Instead of bringing the pistol down to meet the incoming mag, leave the pistol up in the "work area" where you have good visual and are still looking downrange. Twist the pistol so you can watch the mag enter the magwell while still keeping the muzzle downrange, slap in, and then twist back to the target. This allows me to reaquire sights much faster and more efficiently, and I don't feel like I have to "fix" my grip every time I change mags.
Hope this helps