[Styrak]

Right side looking down the sights is the sear reset.
Left side looking down the sights is the valve release. It resets/releases that valve knocker from contacting the magazine once the slide comes back far enough. Basically keeps the valve open to get enough gas through the gun until the slide trips it. So yes that may very well be your problem. The valve knocker is making very light strikes since it can't stay "on". That's my thoughts.