OnUnityAdsDidFinish() repeats when I restart the game

When OnUnityAdsDidFinish () starts, it works, but when I restart the game (load the same scene again), I don't know why, but (when the ad ends) OnUnityAdsDidFinish (), it starts twice. If I restart the game again, the OnUnityAdsDidFinish (). Start three times! Help.

(parameters >> placementId = SkinAdd_Android && showResult = ShowResult.Finished) OnUnityAdsDidFinish() code:

 public void OnUnityAdsDidFinish(string placementId, ShowResult showResult)
 {
     if (placementId == "SkinAdd_Android")
     {
         if (showResult == ShowResult.Finished)
         {
             menu.SkinFinished();
         }
     }else if (placementId == "Continue_Android")
     {
         if (showResult == ShowResult.Finished)
         {
             menu.ContinueFinished();
         }else if (showResult == ShowResult.Skipped)
         {
             menu.ContinueSkipped();
         }
     }
 }