Thanks for everyone's help and recommendations. I've shot thousands of rounds through different guns, so I don't think that it is my grip. However, I will pay more attention to my grip. I am using a rubber grip and cotton gloves. Could that pose a problem?

As far as the magazine, I did notice that there is a narrow spot near the top of the front. The bottom reads .470" but the top reads .462". Also, if I lay the magazine on its side onto a flat surface (with the flange overhanging so as not to interfere, the magazine will rock ever so slightly if I apply pressure to it. That's because it reads .480" on the rear side top and bottom. There is a taper.

I'm not sure if this normal, but the mag seems to have a lot of slop when seated into the well. I may be pressing the mag upward when gripping the gun. Additionally, maybe I am not seating the rounds fully when using the UPLULA speed loader.

I will try another magazine. If it still happens, I will try a different ammo for awhile. I'm sure that the solution to this problem is such an easy fix, but it takes time to troubleshoot.