AB's search facilities are currently running 'on reduced power'.
If you use the 'search site' option, at the top of the page, you'll find that the 'proper' search has been disabled and you'll be transferred to a Google search for relevant posts. If you go to 'My Profile' and click to access the questions you've asked (or answered), AB's internal search engine returns 'timed out' about 90% of the time. That's the same search engine which seeks 'relevant questions' when you submit a new question.
The reduced search facilities have been put in place while AB's techies have been trying to sort out some of the problems with the site. Hopefully everything will be fixed when 'AB 2.0' is rolled out. (The target date is currently somewhere around March or April).
Chris