Remove the slide. Push the locking block pin in about ¼ ways in left to right. Push the trigger pin in about ¼ or more ways in. remove the slide stop lever. Push the locking block pin back in. Install the slide stop lever push the trigger pin back in. If it still does not work you bent the slide stop lever spring.
You will probably have to wiggle the slide stop lever when trying to push in on the trigger pin.
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