Specifically, it's clicking within the menu that appears. Clicking elsewhere on the page will close both. I'm not sure if there's an easy fix to this though.
I'm going to have to call this a design issue I think. The useful searches menu is separate from the search popup in terms of the DOM, so there isn't really a particularly good way to connect the two to indicate the search popup should stay when you click the "child" menu.
Just in case you're not aware, the menu system doesn't work like that. The JS moves them at the end of the DOM and then positions them. Not doing this creates potential z-index issues and--more significantly--worksaround overflow:hidden/auto usage.
Just in case you're not aware, the menu system doesn't work like that. The JS moves them at the end of the DOM and then positions them. Not doing this creates potential z-index issues and--more significantly--worksaround overflow:hidden/auto usage.