Welcome to the FTF, we have an "Introductions" area where you can say "HI" the next time you drop in.
How did the slide stop work with the hollow points?
If both mags started at the same time, then there may be a different problem. Make sure the slide stop did not creep out.
Of course, you did put a drop of oil at all the contact points of the slide stop to make sure that moved freely.
"A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed."
Life Member NRA
Life Member NAHC
Former President of the ECPT (Eifel Combat Pistol Team)