Shield owners- Is it just me or is the slide lock unusable?

I practically have to use the force of a pallet jack to get the slide to close with the slide lock on my new Shield 9mm. If there's an empty mag in the gun you simply can't close the slide, you have to take the mag out. Is this a permanent problem or does the slide lock have a break in period? I've never had this issue with any other handgun via /r/CCW http://ift.tt/291cy84