The bevel below the firing pin hole is, as has been stated, totally normal and part of the design. I’m betting your problem is ammo related. I have around 40K through my issued training M&P 1.0 and well over 10K through my personal training 2.0 CORE - I don’t think I’ve ever touched the striker channel on either.

I just finished up a 10,000 round test on a Trijicon SRO using a 2.0 CORE. The 10,000 rounds were fired in seven shooting sessions. The slowest firing was 1,000 rounds in a bit over an hour. The last 2,000 rounds were fired in about 35 minutes. The pistol was cooled by dunking the slide/barrel in water and watching out for the steam and splashing boiling water coming up through the magazine well. I did do a couple quick cleanings of the pistol during the test but never pulled the striker assembly.

We’ve got guys who have hundreds of thousands of rounds through M&Ps with abusive training cycles and minimal maintenance. The most common problem is ammunition that doesn’t go bang. In some cases a heavier primer strike ( like Beretta with the Mil-Spec hammer spring) will make them go. In most cases it won’t.

I’d use some of your proven ammunition and put a few hundred rounds through the pistol in practice. I’ll bet it runs fine.