我想限制关键字搜索，只搜索确切的单词，而不是短语或混合内容，所以如果我搜索cheese，它需要限制只搜索单词cheese，现在它也会返回单词cheeseburger的内容。
我修改后的模板查询中的搜索查询部分就在这里：

if ( ! function_exists( 'get_job_listings' ) ) :
    if ( 'top_rating' === $args['orderby'] ) {
        $query_args['meta_query'] = [
            'relation' => 'OR',
            [
                'key'     => 'rating',
                'compare' => 'EXISTS',
            ],
            [
                'key'     => 'rating',
                'compare' => 'NOT EXISTS',
            ],
        ];
        $query_args['orderby'] = [
            'meta_value_num' => 'DESC',
            'comment_count' => 'DESC',
        ];
    }

    $job_manager_keyword = sanitize_text_field( $args['search_keywords'] );
    if ( ! empty( $job_manager_keyword ) && strlen( $job_manager_keyword ) >= apply_filters( 'job_manager_get_listings_keyword_length_threshold', 2 ) ) {
        $search_query = $job_manager_keyword;
    $query_args['s'] = $search_query;
        // $query_args['s'] = '"' . $search_query . '"';
        // $query_args['s'] = '/\b' . preg_quote($search_query, '/') . '\b/';
        $query_args['sentence'] = true;
        add_filter( 'posts_search', 'get_job_listings_keyword_search' );
    }

    $query_args = apply_filters( 'job_manager_get_listings', $query_args, $args );

    if ( empty( $query_args['meta_query'] ) ) {
        unset( $query_args['meta_query'] );
    }

    if ( empty( $query_args['tax_query'] ) ) {
        unset( $query_args['tax_query'] );
    }

    /** This filter is documented in wp-job-manager.php */
    $query_args['lang'] = apply_filters( 'wpjm_lang', null );

    // Filter args.
    $query_args = apply_filters( 'get_job_listings_query_args', $query_args, $args );
    do_action( 'before_get_job_listings', $query_args, $args );

    // Cache results.
    if ( apply_filters( 'get_job_listings_cache_results', true ) ) {
        $to_hash              = wp_json_encode( $query_args );
        $query_args_hash      = 'jm_' . md5( $to_hash . JOB_MANAGER_VERSION ) . WP_Job_Manager_Cache_Helper::get_transient_version( 'get_job_listings' );
        $result               = false;
        $cached_query_results = true;
        $cached_query_posts   = get_transient( $query_args_hash );

        if ( is_string( $cached_query_posts ) ) {
            $cached_query_posts = json_decode( $cached_query_posts, false );

            if (
                $cached_query_posts
                && is_object( $cached_query_posts )
                && isset( $cached_query_posts->max_num_pages )
                && isset( $cached_query_posts->found_posts )
                && isset( $cached_query_posts->posts )
                && is_array( $cached_query_posts->posts )
            ) {
                if ( in_array( $query_args['fields'], [ 'ids', 'id=>parent' ], true ) ) {
                    // For these special requests, just return the array of results as set.
                    $posts = $cached_query_posts->posts;
                } else {
                    $posts = array_map( 'get_post', $cached_query_posts->posts );
                }

                $result = new WP_Query();
                $result->parse_query( $query_args );
                $result->posts         = $posts;
                $result->found_posts   = intval( $cached_query_posts->found_posts );
                $result->max_num_pages = intval( $cached_query_posts->max_num_pages );
                $result->post_count    = count( $posts );
            }
        }

        if ( false === $result ) {
            $result               = new WP_Query( $query_args );
            $cached_query_results = false;
            $cacheable_result                  = [];
            $cacheable_result['posts']         = array_values( $result->posts );
            $cacheable_result['found_posts']   = $result->found_posts;
            $cacheable_result['max_num_pages'] = $result->max_num_pages;
            set_transient( $query_args_hash, wp_json_encode( $cacheable_result ), DAY_IN_SECONDS );
        }

        if ( $cached_query_results ) {
            // random order is cached so shuffle them.
            if ( 'rand_featured' === $args['orderby'] ) {
                usort( $result->posts, '_wpjm_shuffle_featured_post_results_helper' );
            } elseif ( 'rand' === $args['orderby'] ) {
                shuffle( $result->posts );
            }
        }
    } else {
        $result = new WP_Query( $query_args );
    }
    do_action( 'after_get_job_listings', $query_args, $args );

    //remove_filter( 'posts_search', 'get_job_listings_keyword_search' );
    return $result;
}

endif;

字符串
我可以看到$query_args['s']是搜索关键字的标准查询，但我尝试过的一些标准查询修改如下所示：

• Make a WordPress query search match exactly the search term（第一个字符）
• WordPress exact search query
• Query for exact word search

还有其他的例子，但没有一个对我有用。
我如何修改它，使它只能搜索内容中的确切单词？
我看到这个问题已经发布了很多次，但我尝试过的所有例子都不起作用。