Load Scene from Asset Bundle, lose gameObject Hierarchy order?

Hi guys, I create an asset bundle from my scene in Unity 5 and I try to load it from www.

 using UnityEditor;
 
 public class CreateAssetBundles
 {
     [MenuItem("Assets/Build AssetBundles")]
     static void BuildAllAssetBundles()
     {
         BuildPipeline.BuildAssetBundles("AssetBundles", 0, EditorUserBuildSettings.activeBuildTarget);
     }
 }

I load the scene by this code

 IEnumerator DownloadAndCacheScene()
     {
         // Wait for the Caching system to be ready
         while (!Caching.ready)
             yield return null;
 
         Debug.Log("start load");
 
         // Load the AssetBundle file from Cache if it exists with the same version or download and store it in the cache
         using (WWW www = WWW.LoadFromCacheOrDownload(BundleURL, version))
         {
             StartCoroutine(UpdateProgress(www));
             yield return www;
             Debug.Log("get www");
             if (www.error != null)
                 throw new Exception("WWW download had an error:" + www.error);
             AssetBundle bundle = www.assetBundle;
             bundle.LoadAllAssets();
             Application.LoadLevel(SceneName);
 
             Debug.Log("instant asset");
             // Unload the AssetBundles compressed contents to conserve memory
             bundle.Unload(false);
 
         } // memory is freed from the web stream (www.Dispose() gets called implicitly)
     }

The scene was loaded well but the only problem is the order of gameObject in Hierarchy is not right.

The parent-child order is right but the child-sibling order is not right.

Some help would be appreciated. Thanks.