S&W M&P9 Shield Semi Automatic Pistol 9mm Luger 3.1" Barrel 7 Rounds Polymer Frame Black Finish 180021

Ordering and shipping was easy and fast enough. On first inspection of the pistol we (FFL and I) discovered the slide would not lock back with either empty magazine inserted. Further inspection shows the slide is not retracting all the way back causing this malfunction. Appears to be an issue with the 2 stage guide rod getting hung up or possibly the spring not seated on the guide rod properly. Didn't even make it into my possession. Sending to S&W