Ditto.Had one, then I bought a Taurus 709. The Taurus 709 is the same size, has a far better trigger, and is far more comfortable to fire. Oh and it actually comes with two mags. After shooting them back to back, I got rid of the PF-9.
There's nothing wrong with the PF-9 though.
It may be as simple as gunk in the firing pin area.... but the manual specifically states not to take it that far apart and to return to Keltec if that disassembly is necessary.
because of its light weight I've found myself not shooting it as often as my other guns because the PF-9 is like a little gremlin in your hands.