There has been a few reports of problems with WWB ammo.
So I would try another brand to rule that out.

I have had a similar experience a couple of times when I have two different pistols at the range with me.
If the grip on each are different, I have found that my thumb was riding the side of the slide.
Sometimes it would cycle fine.
But a few times it wouldn't drive the round home.
A good smack on the back of the slide corrected the problem.

Might not be your problem, but a suggestion none the less!!
Sorry for the troubles! Let us know how it turns out!!
Best of luck!

__________________
~ "JJ"