So, I have read of issues of some people having problems with Glock 36 mags with Pierce +1 extensions not feeding the last round, and using Wollf overpower (or whatever they call them) springs to fix this issue.
NOT my question
I just got a (used so i do not know the spring in it) +1 set up mag. If I insert it in the pistol, slide forward, and rack the slide, on the first round i can feel the slide catch on RETRACTING the slide (feeds fine on release) All subsiquent rounds work fine (hand working the slide)

Anyone have a similar issue? or hear of such?
Thoughts (yeah, i am probably going to convert back to standard mag baseplate and order factory mag spring to start, but still, maybe someone has an idea I haven't thought of)