Magazines are the Achilles heel of a semi-auto.
If your firearm is under warranty, go that route first.
Because it seems to happen with different magazines, I would suspect the slide stop itself.
"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)