MP SHIELD 40 Cal slide wont lock back even with a mag inserted

Hello again all. I have been fighting with my mp shield since its last cleaning. I have never ran into this. MY slide wont lock back no matter what. I have read in forums that inserting the mag causes the slide to auto lock. I am trying to figure this out myself as I dont have the money to take this to a guns smith here. Any advice ?

Update::...I was messing with it and it just suddenly it just fixed its self. Wish it did before I posted......thanks anyways yall

Welcome to the forum. Do you keep one round loaded in the magazine, and stored it in your breast pocket? ;)

Had you disassembled it prior?

I really miss this forum from around seven or eight years ago.