Not trying to take this off topic or criticize your purchase,...but,...in studying as much about this sort of thing I could before I decided which AR-based 9mm system to buy, I opted for the CMMG Banshee rotary semi-locking system, and I've been extremely satisfied. Primarily because it hasn't produced any such issues regardless of ammo type I've fed it.
I assembled mine from parts rather than as a factory gun, and I had a standard carbine buffer laying around so I used that just to test fire it, fully intending to replace it with a heavier one. But the damned thing has worked perfectly fine since day one and I left it in there. Had it for 4 years now and hasn't choked once. I primarily shoot 147-165 grain heavies with it, but it has eaten everything.