On native iOS, when you have a sheet open with scrollable content, if you start scrolling, it will scroll normally. But then when you drag downwards, once you reach the top of the scrollable content, the sheet starts it's drag to dismiss gesture. Then if you drag back up again, once the the sheet reaches it's original height, the nested scroll starts back up again.

In Flutter currently we can either give the nested scroll or the drag to dismiss gesture priority. And we can't switch back and forth between either animations on one drag event.