I would say that yes the spring is either weak or broken.
I am not sure as to how to open the slide up to look. Some will chime in I am sure.
Yu could all ways contact S&W as well to see if it could be a warranty thing,
Did you buddy mess with it at all in regards to changing the spring out.
Or it could just be really dirty an hanging up that way.
You might try using a good canned cleaner that you can spray with force in an around the strike pin.
Make sure the cleaner is plastic safe.
I know there is a hole on the bottom of the slide as well were it lead right to the striker.
you could try a little oil an work it back an forth.