When you transition the NTP between above and below the fold, the omnibox will jump down and up. This is due to the calculation of the scroll amount in the RecyclerView. The omnibox position is dependent on the amount of scroll.

RecyclerView approximates the amount of scroll using an average of the currently shown ViewHolders. Since the first ViewHolder takes up most of the screen, this number is way off, hence RecyclerView readjusts its scroll estimates when it gets to the below the fold cards and the ombinox position calculation changes.

Note: This may be fixed by 596416.