WT: Welcome to DefensiveCarry, by the way.
I had a PM9, as well. Like you, mine experienced many failures to cycle properly. I sent it back to the shop after having had exchanges with them via email for awhile, regarding the experience I was having with it, after trying a few changes to isolate the problems. In the end, it was the pistol's "tight" nature that caused it to be fussy. After it came back from Kahr, after a barrel replacement, polishing up of the feed ramp and throat, things were vastly improved. Though, by that time (~700+ rds), my confidence had been shaken. The last several hundred rounds were nearly flawless, when I sold it.
There seem to be many reports of this sort of experience. Though there seem to be many more reports of excellent operation well into the thousands of rounds. My guess is that my problem is indicative of a general reality with the PM9: they're made a bit tighter, with less tolerance, which can make them finicky with choices of ammo until they're really broken-in.
And I'm not talking about the Kahr "standard" minimum period of 200rds. I'm talking about a given tight gun being broken-in to the point it gets highly reliable. My only other experience with a fairly tight gun was a Browning BDM I once had. (Never should have sold it, but that's another story.) It was a less than reliable until it approached 10K rds, at which point it got nearly perfect. It would swallow all ammo, of almost any length, ball or JHP, SP or wadcutter. When I sold it, it was approaching 40K rds, and it had experienced several years' worth of perfect shooting: no failures to feed, cycle or eject, of any sort.
On that BDM, a gunsmith's minor attentions, early on, helped convince me the steel was somewhat tougher and harder to work on than the average material in most modern pistols. He had a devil of a time doing basic polishing and improvements in the slide-to-frame smoothness, the barrel's feeding area (ramp, throat). After the work, though, after having been opened up to be a bit more tolerant of slightly "off" ammo, it was flawless.
Now, none of this is to suggest that your Kahr will do the same thing. And my experience with just the one PM9 is hardly sufficient to suggest that it'll do the same thing. But, a lot of folks find that 200rds simply isn't a sufficiently-long break-in period on guns that are known (or suspected) to have harder material in the steel of the areas to be "polished" or smoothed. My BDM had that, as did my PM9. The Norinco 1911-style pistols are known for it, among gunsmiths. You hear of others, from time to time.
The point is: why not give it to Kahr with a solid explanation of what you suspect to be true, having them work on the gun from the point of reliability, indicating that you're willing to sacrifice some of the "match" tightness in order to gain reliability to handle cycling of most any ammo. You're wanting "street" reliability, not match reliability, I'm guessing. See what they can do. Couldn't hurt. Another gunsmithing shop that's known for tuning Kahrs (ie, Cylinder & Slide) might do you very well, too, but it'll cost ya. Your experiences also seem to entail a few things going on, some of which are unrelated to the general ability of the gun to cycle cleanly. Be sure to know what's what, when going after a certain gunsmithing step or two.
Good luck, with whatever you decide.