Sort out of stock products at the end in search results page

Hi,

I am trying to sort out of stock products at the end of product list in search results page, but I can’t. I have add this code:

function _nok_order_by_stock_status($posts_clauses, $query) {

// Check if 'orderby' exists in the posts_clauses and if 'order' request parameter is set to 'desc'
if (isset($posts_clauses['orderby']) && isset($_REQUEST['order']) && strtolower($_REQUEST['order']) == "desc") {
    $posts_clauses['orderby'] = str_replace("ASC", "DESC", $posts_clauses['orderby']);
}

// Check if the query is the main query and if it's a product category, tag, taxonomy or shop page
if ($query->is_main_query() && (
    (function_exists('is_product_category') && is_product_category()) ||
    (function_exists('is_product_tag') && is_product_tag()) ||
    (function_exists('is_product_taxonomy') && is_product_taxonomy()) ||
    (function_exists('is_shop') && is_shop()) || is_search()
)) {


    global $wpdb;

    // Join the postmeta table for stock status and price
    $posts_clauses['join'] .= "
        LEFT JOIN (
            SELECT post_id, meta_value 
            FROM $wpdb->postmeta  
            WHERE meta_key = '_stock_status'
        ) istockstatus ON ($wpdb->posts.ID = istockstatus.post_id)
        LEFT JOIN (
            SELECT post_id, meta_value 
            FROM $wpdb->postmeta  
            WHERE meta_key = '_price'
        ) prezzo ON ($wpdb->posts.ID = prezzo.post_id)";

    // Modify the orderby clause to prioritize out of stock products with a non-zero price
    $posts_clauses['orderby'] = "
        CASE
            WHEN istockstatus.meta_value = 'outofstock' AND prezzo.meta_value != 0 THEN 1
        END ASC, " . $posts_clauses['orderby'];
}

return $posts_clauses;

}

// Add the function to the 'posts_clauses' filter with a priority of 2000
add_filter('posts_clauses', '_nok_order_by_stock_status', 2000, 2);

It works perfectly on product categories, but in search results nothing goes right.

What can I do?

Please help,
thanks in advance.