Make sure the recoil spring is installed with the tight end toward the slide stop.

Ty a different magazine (e.g., Wilson). This pistol comes with Novack magazines, which tend to release the cartridge earlier than ones with parallel lips.

Check your ammo. The chamber is tight. I've had some rounds, both Winchester and Remington, fail to feed completely. The same round jammed twice, and didn't respond to a slap on the rear of the slide. The next rounds were OK.

Have a qualified gunsmith (or S&W) take a look at it. The timing could be a bit off, or the extractor needs tuning.