When you start a new (advanced) search, the initial query constraints include new/open/reopened statuses as always, but now also includes type = DEFECT which I think is a recent change (due to BZ upgrade?).

Obviously sometimes you do want to search only DEFECTs but I think it is more common to want to leave this field unconstrained. It is confusing (*) and irritating to, say, select a component and subcomponent, type API in the Keywords field, and search only to find no results... then realize that the search was limited to DEFECTs when the desired result was likely an ENHANCEMENT.

If there is a way to customize initial search fields in preferences, I did not find it.

(*) In fact at my font size and screen resolution, in the search form page the "Issue Type" list is only partly visible at the bottom of the screen, with just DEFECT showing, so it is not apparent without scrolling down that the other two items in the list are not selected! Contrast this with "Status" which is prominent at the top center of the screen where it is clear that RESOLVED/VERIFIED/CLOSED are excluded.