Input.GetAxisRaw("Mouse ScrollWheel") 4 times

I tried to reproduce the problem and failed, which hints that it is a hardware issue rather than a Unity issue. $$anonymous$$y test:

  var f : float = Input.GetAxisRaw("$$anonymous$$ouse ScrollWheel");
  if (f != 0.0) {
       Debug.Log(f+", "+Time.frameCount);
  }

You might try increasing the dead zone for this axis to see if it fixedsthe problem. You can also code around the issue since $$anonymous$$ouse ScrollWheel returns 1.0:

     var f : float = Input.GetAxisRaw("$$anonymous$$ouse ScrollWheel");
     if (f > 0.5 || f < -0.5) {
         // Take action here
     }