I’m trying to sort a query according to the order they write it in but it takes an order by ID.

The variable $idpaginas prints: 20659,20626,20585,20616,18464,19748,19991,18520,20588,21268,18753,20556,21277,18829,18551,21132

But after the query, it prints: 18520,18520,18551,18753,18829…..

function LoopMode($atts, $output = null, $my_query = null, $query_args = null) {
    // Params extraction
    extract(shortcode_atts(array(
        'idpaginas'   => '',
        'style'       => '',
    ), $atts));

    $query_args = array(
        'post_status'    => 'publish',
        'post__in'       => explode( ",", $idpaginas ),
        'posts_per_page' => -1,
        'post_type'      => 'page',
        'order_by'       => 'post__in',
        'order'          => 'ASC',
    );
    if(empty($style)){ $style="2"; }
    // Run query
    $my_query = new WP_Query( $query_args );
    //$output="";
    while ($my_query->have_posts()) : $my_query->the_post(); ?>
        <div class="cluster-box col-<?php echo $style; ?>">
            <a href="<?php the_permalink() ?>" class="cluster-mcl-link">
                <div class="mcl-cluster">
                    <div class="mcl-cluster-img" style="background-image:url(<?php the_post_thumbnail_url(); ?>);">
                        <div class="mcl-cluster-title"><h3><?php the_title(); ?></h3></div>
                    </div>
                </div>
            </a>
        </div>
    <?php endwhile;
    $my_query = null; $my_query = $temp;
    $output = ob_get_contents();
    ob_end_clean();
    wp_reset_postdata();
    return $output;
}
add_shortcode('cluster', 'LoopMode');

I have tried to remove args “order_by” and “order” values but it still continues to order it as he wants.

Thanks!