I'd look at the orientation of the slide lock spring. It may have worked loose enough to rotate and not have enough pressure on the lever. Often times it's just a matter of loosening, rotating a bit and retighten. Just snug, don't overtighten.
There's a good Greg photo someplace around here. Search for slide lock spring and it should pop up.
In Memory of Paul "Dietrich" Stines.
Dad: Say something nice to your cousin Shirley
Dietrich: For a fat girl you sure don't sweat much.
Cue sound of Head slap.
RIP Muggsy & TMan
"If you are a warrior legally authorized to carry a weapon and you step outside without that weapon, then you become a sheep, pretending that JOCKO will not come today."