That can mean that the bolt is stuck forward past the sear.
If you look up into the mag well, can you see the tip of the bolt protruding into the breach more than usual?
If this is the case, undo and remove the bolt and slide the post out from the back of the grip frame (the bit that has the strap ring on it). Then just try to lift the grip frame away from the body and you should hear and feel the bolt reset hopefully.
Hopefully that makes sense and solves the issue for you.