Filter panels stay open while you scroll their list

In the filter bar on Conversations and on the reports, scrolling inside an open filter panel closed it. A list longer than the panel, like Issues, couldn't be scrolled to reach its last options. This happened on desktop and on mobile.

The panel now stays open while you scroll its own list. It still closes when you scroll the page behind it, so it never drifts away from the filter that opened it.