scrollToPosition() scrollTo() restoreInstanceState() do not scroll and keep recycler at the top

First thank you for this amazing library, it saves me a lot of time.

I have tried to dig deeper into your code to understand why the scroll dos not work.
The following methods do not scroll : 
- scrollToPosition() 
- scrollTo() 
- restoreInstanceState()
I keep searching but I don't understand why.
I think there is something I don't understand.
Can you help ?