Create a tall post with some images.
Now click Edit
Result: the post vanishes and you're left lower down the Flow board. You need to scroll up to find the edit form. This happens because the edit form (textarea + buttons) is much smaller than the post.
This sounds like a variation of bug 59834. Maybe the form needs a conditionalScrollIntoView(). If you click Preview to see the big post then click Keep editing, the textarea does scroll into view (incompletely on Firefox, you don't see the top of it)