I purchased my VP9 barely a year ago. The very first time I took it to the range the slide stopped locking back after about 100 rounds. First it would release while loading a new magazine. Then it started releasing regardless of loading a mag, if a mag is present or not. Of course my first thoughts were my grip. Unfortunately it made no difference. I can hold it at the bottom of the grip and just barely shake it and it will release. I even ordered a new slide lock and replaced it. It helped for about a week and has returned to releasing at will just from regular testing not even being shot. I have even had it release with no movement if I just wait long enough after locking it. Any insight would be very much appreciated.