Strange LoadSceneAsync behaviour

Hi guys!

I am working on a VR game for Vive and Oculus and I am currently dealing with a strange behaviour when I switch between two scenes.

Scene 1: realtime lighting, up to about 300k tris
Scene 2: baked lighting, about 60-70k tris when initially loaded

In order to switch from Scene 1 to Scene 2 I have created an intermediary loading scene that contains just a canvas with loading text.

My scene load logic looks something like this:

Code (CSharp):

1.     private IEnumerator LoadNewScene()
2.     {
3.  
4.         Application.backgroundLoadingPriority = ThreadPriority.Low;
5.         async = SceneManager.LoadSceneAsync("Scene2");
6.  
7.         while (!async.isDone)
8.         {
9.             yield return null;
10.         }
11.  
12.     }

Moving from Scene 1 to the loading scene is almost immediate. The problem and the strange behaviour comes when moving from the intermediary scene to Scene 2 which is more complex as mentioned above. It takes a lot of time - about 30 seconds... I have tried to disable all objects in Scene 2 but the time is the same which is again strange.

Other thing which I think that is strange is that when I try to load Scene 2 directly from Scene 1... it loads in like... 3 seconds!

Am I missing something in the way Unity is loading the scenes? Is this behaviour normal?