If best results don’t come up first and changing weighting settings doesn’t seem to make any difference, there couple of things you can do.
Is Relevanssi active?
The first thing is to check if the results are actually provided by Relevanssi. If you disable Relevanssi, do the results change? Do you see Relevanssi-generated excerpts? There are different reasons why your search results may not come from Relevanssi even if Relevanssi is activated, and the most common has to do with query posts calls. For that, see this Knowledge Base entry.
Are the results in menu_order?
I’ve seen several cases where odd search results are caused by a theme (or a plugin) that forces the search to use menu_order, for some reason. If that’s the problem, the solution is simple. Add this code to your theme functions.php:
add_filter( 'relevanssi_orderby', function ( $orderby ) { return 'relevance'; } );
After debugging for hours I found you need to make sure your functions.php doesnt have;
add_filter(‘facetwp_use_search_relevancy’, ‘__return_false’);
AND
function [theme_name]_facetwp_alter_sort_options($options, $params) {
return [];
}
add_filter(‘facetwp_sort_options’, ‘ [theme_name]_facetwp_alter_sort_options’, 10, 2);
Both of these will skip the Relevanssi sorting