Counter is not working correctly with LeanTween

The counter is not working correctly with leantween animation line. When I deleted the leantween line, it is working correctly. How can I fix this?

 public static void solveMatches(List<Gem> matches) {
             foreach (Gem g in matches) {
                 //I am trying to add here a destroying animation
                 LeanTween.rotate (g.gameObject, new Vector3(0.0f, 270.0f, 0.0f), 0.5f).setDestroyOnComplete(g.gameObject).setEase(LeanTweenType.easeOutQuad);
                 soundControl = true; //destroy sound 
                 ++count;
             }