Same problem as https://www.joomlart.com/forums/d/36320-base-url-being-duplicated-in-search-results ; however package not updated yet.
Effective solution for me is change helper.php in content plugin:
//$item->url = JRoute::_($route); $uriLeng = mb_strlen(JUri::root(true)); $item->url = mb_substr(JRoute::_($route), $uriLeng);
marty-harty Is that working now on your site?
Yes, with the K2 content plugin. Thanks