https://github.com/OnTheGoSystems/wpml-elasticpress/blob/68a77ba18a0eddd7da115029c28ecde9e3b8b1dc/src/LanguageSearch.php#L45 Im getting no results on the main language sites, using sub directories for languages. site.com/ site.com/en site.com/de Fixed by changing line 45 to: 'post_lang.keyword' => $this->getQueryLang(),