Hey guys, I'm new to the forum. I just bought my first m&p about 2 weeks ago. Finally got a chance to take it out and run it today and the slide isn't locking back on last round. After 8 to 10 mags it didn't lock back a single time. I even tried tracking the slide with an empty mag to see if thatd do it and it didn't lock back then either. My thumb isn't on the slide stop while shooting so that's not the issue. It's an m&p pro series 2.0, 5in slide. Any help would be greatly appreciated.