Rimlock is a problem for many .32ACP pistols & Keltec is one of them. Unlike other ACP calibers, the rim of a .32 can catch in the groove of the round below it. As the top round feeds, it drags the next round forward & the rim of that second round catches in the groove on the one below it, preventing it from being fed.
The problem is caused by the fact that HPs are shorter than FMJ & can be fixed with an adapter that goes in the mag & holds the HP rounds forward in the tube. The downside to that is that the adapter has to be removed when you want to shoot FMJ. An adapter can be made with a wire/paperclip. If I can find the video, I'll come back & post it.
Another solution is to chamber a HP & load a HP as the top round in the mag, with other rounds all being FMJ. This eliminates the rimlock problem.