Create a column with a header and more than 10 items.
Add an autofilter
Click on the filter's "down arrow"

Expected result:
A selection box containing all the choices from that column, showing more than 10 items, with a scroll bar. (This used to happen.)

Actual result:
The selection box shows only one item, and so it is (vertically) too small to support a scroll bar (the scroll arrows are there, but it takes a lot of time to use them to scroll through a long list).

Desired resolution: If the selection box were always long enough to show more than 10 items, then I believe that the scroll bar would be usable.