Scrolling won't reset after flexing

[wrangelvid]

Let's start with many items in a container that can scroll vertically. We start out with the outer container being compressed such that the rows have to flex, and we scrolled to the bottom. When increasing the width of the viewport (which increases the width of the container), more items fit in the rows. However, our scroll position doesn't change. Worse, when there is no overflow anymore, we can't scroll anymore and are left somewhere far down in the container where none of the items are visible.
(Send a video to @bbohlender )