Relevanssi 3.5.5 is out now and available from the plugin repository.
- 500 errors caused by arrays in custom fields should be gone now.
 - Improvements to the ACF “select” field support.
 - Relevanssi will not break when frontend plugins insert posts.
 relevanssi_matchfilter has a new parameter, which contains the search term.- Polylang support has been improved.
 - WPML and Polylang filters work when “fields” is set to “ids”.
 - New filter: 
relevanssi_log_get_usergets passed the user object before Relevanssi decides if the query should be logged or not.