The player with Mecanim controller loaded by assetbundle can not work well when changing levels.
(1) load the player assetbundle, and use Unload(false) to remove the www.assetbundle structure.
(2) Instantiate the player and set it "DontDestroyOnLoad", and it can work well.
(3) Change to anohter scene, you can see that the player can not work well. It seems that something in Mecanim controller is missing. But it should be unloaded, because it always has reference to the player gameobject.