when my M&P 9MM FS has some of the same issues, I made sure the mag lips were smooth with no burrs and after about 200 rounds of break in, it has never failed. It now has several thousand rounds through the gun and never misses a beat.
Once I got used to my M&P 9 full size and compact, they shoot very well for me. As a matter of fact if I do my part, they are boringly accurate at 20 yards.
I had a Jennings when I was a teenager, I never had a problem with it and shot it every weekend for years. Never did know they had a bad reputation until about 25 years later. Should have kept it.