Check this out-
YouTube - Kahr PM9 - Very Good But Has Problems with Magazine
This explains the issue I had with both my PM9's - the inability to manually clear a dud from the chamber with the standard "tap, rack, bang" method. With JHPs, I would always get the top round in the mag jammed into the feed ramp. This explains why - and that it seems to be a design issue. The top round in the mag assumes a nose-down attitude.
Smacking the back of the slide, or upwards on the bottom of the mag, sometimes got the round to feed.
Good issue to be aware of...