Its not that, scroll down is just missing entirely when setting a kingdom filter for weapons specifically. Happens in and out of the event, for every kingdom. Not sure if this is a new bug or not, never paid attention before now.
drag down to
or (filter Broken Spire weapons)
drag scroll to
Dragging back up also makes the scroll arrows disappear again.
Actually, it appears to be any set of filters where you have exactly 9 or 10 options available. The scroll bar won’t show until there are 11 items to show. Almost like the calculation to see if scroll bars should show when scrolled all the way up uses the assumption that there are 5 items per row, when there are in fact 4, but every row beyond that seems to correctly use 4.
Filtering yellow-red combination weapons on an account missing two yellow-red weapons (has 9, no dawnbringer or fleshripper):
Same account, but setting the filter to all weapons (11 weapons total with this color combo)
An account that owns 10 of these weapons (no dawnbringer) still doesn’t have the scroll bar.
Same thing if you set the filters to get exactly 9 or 10 different troops:
TL;DR: Any combination of weapon or troop (and possibly even pet) filters that results in 9 or 10 results will result in the scroll bars being absent when scrolled all the way to the top. 11 or more results has them show correctly. The scroll bar should appear starting at 9 items. Suspect the check to see if the bar should appear while all the way at the top uses the wrong value (> 10 instead of > 8, or assumes a column width of 5 when only 4 are displayed). Does not appear to be an issue for any page past the first page.