Recently purchase a M&P 9mm shield. Prior to taking it to the range for the first time I was able to field strip with no issues. Took it to the range this past weekend put about 150 rounds with no issues at all. When I got home, I attempted to field strip and have not been able to get the slide off the frame. There is a silver wire right above the take down lever that is preventing the slide to come off. Has this happened to anyone? Should I contact Smith or a local gun smith?