I've had an LC9 now for about a year and never had a single issue, It's seems to eat whatever I put through it including the crappy Wolf steel case.
I think someone else here had a good thought, You may be engaging the slide lock while shooting, it happens more often then you'd think.
I had a PF9 Kel-Tec I bought a few years ago that I had nothing but problems with, mainly rounds nosediving into the magazine, everyone told me I was limp wristing which is funny because I never had that problem with any of the other 50 or so handguns I own, Got rid of the PF9 for the LC9 -- I've since bought a more recent production PF9 and it has been every bit as reliable as the LC9 - I think I just got a lemon first time around, But I sold it to my brother with a full understanding of the problems I was having, I'm not even sure if he's shot it yet to verify. I suspect it was more a Magazine issue than anything, Kel-Tec sent me a new mag that was a little different than the ones I had, I never had any problems with the new magazine.
Anyway, The LC9 seems to be a great gun, I find it good enough to trust my Life on as it has become my EDC gun.
TJB