Well..... upon close inspection under magnification, I now see the problem with the last shot hold open. Both the slide stop and the notch in the slide display obvious signs of deformation where the two pieces contact each other. Instead of both parts meeting squarely, they each have a bit of angle now. I'm really surprised there is enough forward motion in the slide, at that short part of the stroke before it catches, to have caused such damage. Regardless, this one's gotta go back to CZ. If I can get any macro photos to post here, I'll show you what I found.

I don't know if this has any correlation to the last shot fail to feed issue but I guess that is a moot point now. Given the damage to the notch in the slide, I imagine they will replace the gun. Can't just replace the slide since the slide, barrel and frame all have the serial.

I sent the pistol to CZ and received it back within a week. IF nothing else, they are prompt. But they also managed to eliminate the problems from my pistol. The work the did included:

1. replace slide stop
2. debur and square the notch in the slide where the stop catches
3. replaced magazine springs with custom Wolff springs
4. tweaked the magazine feed lips
5. polished the chamber

I have since put about 150 rounds though the gun without a hitch. I hope the fix holds but have no qualms about sending it back to the again should the need arise.

I'm glad you got it fixed.

Congratulations.