OK, the way to fix it is to remove the frame assembly from the grip, then heat the grip with a hair dryer (or heat gun on low) and eliminate the bulge. The bulge allows the spring to slip past the ejector/slide stop, and hinders it from going back down.
Before we go any further, we need to look at the red arrow in my pic. It points to the hole on the far (right) side of the frame. Please inspect yours and see if it looks perfectly round and all the black anodizing is intact. It shouldn't be marred or "egged out". Let me know what you find.