When you are using the Abandoned Cart Recovery plugin by Addify, FacetWP will detect the wrong query for your post/product listings, causing the facets to not appear.

Add the following code to your (child) theme’s functions.php to fix this issue:

<?php
add_filter( 'facetwp_is_main_query', function( $is_main_query, $query ) {
    if ( 'addify_acr_carts' == $query->get( 'post_type' ) ) {
        $is_main_query = false;
    }
    return $is_main_query;
}, 10, 2 );

See also