why I get onLayoutChildren called every time when onBindViewHolder is called(when add one view)

Question

I'm using my own custome LinearLayoutManager for the RecyclerView. I need to dynamically add one view if user scroll or move the list by button. When getViewByPosition is called, the onBindViewHolder is called also. And then, onLayoutChildren is also called every time when the list scrolls by one position.

Any one knows the potential reason for this? Thanks