DISCLAIMER
It was not a goal to have search fully operational in bugzillapreview, although we agree that it is convenient to have a functional search there for better testing. Genuine search bugs must be reproduced in https://phabricator.wikimedia.org
When I search for a bug # by using the search field I get a curl error --
eg
72473 results in:
Unhandled Exception ("HTTPFutureCURLResponseStatus")
[cURL/7] (http://localhost:9200/phabricator/TASK,CMIT,MOCK,PROJ,QUES,DREV,USER,WIKI/_search) <CURLE_COULDNT_CONNECT> The cURL library raised an error while making a request. You may be able to find more information about this error (error code: 7) on the cURL site: http://curl.haxx.se/libcurl/c/libcurl-errors.html#CURLECOULDNTCONNECT