Of the three mags that I have, one when installed empty will not allow the slide release lever to move to close slide. The other two will. The only thing that I can see is on that mag the follower protrudes out of the mag more than the others. Could that be the problem. Any comments would be appreciated. It does feed the ammo with no problem.
Pull your slide off and put the stop lever back in to see how it's meeting the follower in the mag. Could be the follower is slipping beside the lever and binding it. Could be a stronger mag spring just causing more resistance.