devel: Scroll bar does not work in Patch Request

When I try to use the scroll bar to scroll in a drop-down list in Patch Request Form (devel), i.e. choosing "Add a patch action" -> e.g. "building" (but it's also true for the other fields) and then clicking the scrollbar, it just closes the drop-down list. Tested in Google Chrome and Firefox.

It is still possible to type something and thereby shorten the drop-down list.