Particular issue with M&P? First I've heard that but know their triggers aren't popular. Also M&P full/compact and Shield have different triggers.
It's not unique to the M&P. However, until recently, the M&P has universally had a mediocre trigger.
Also, the M&P line comes with a heavy trigger. The pull is between 6-7lbs. This is OK, but a little heavy for most shooters.
Here's what happens...
The shooter goes to the range with his new gun. Because it's the first shot(s) he takes his time. Gun pointed in, finger on the trigger, hard focus on the front sight, pressssss...bang! The very first round hit's almost dead center. Ah, the gun works.
Next shot, same thing only this time it's low and left. Next time, low-left. Slow down and still low-left. By the end of the magazine we feel like the gun is malfunctioning. It's not, but we can't hit in the center.
Because the trigger is heavy, and we're trying to press the trigger evenly, we tend to flinch ever so slightly just before it fires.
So, try the rest first, but then try this: Press the trigger a little quicker. Don't slap at it, but keep an even press straight back. Just don't try to do it too slowly; just faster than you were before. I'm not guaranteeing this will work, it's just something to try.
Also, do you have the right grip? Without that, you're just spinning your wheels.