Why doesn't AJAX work intermittently in Wordpress?

Question

WordPress

Good afternoon.
I created a custom post type in WordPress, for this custom post type I wrote a paginator in Ajax. The paginator code in the functions.php file looks like this:

add_action('wp_ajax_paginate_action', 'paginator_callback');

function paginator_callback()
{

    $args = [
        'posts_per_page' => $_POST['limit'],
        'offset' => $_POST['offset'],
        'category' => '',
        'category_name' => '',
        'orderby' => 'date',
        'order' => 'DESC',
        'include' => '',
        'exclude' => '',
        'meta_key' => '',
        'meta_value' => '',
        'post_type' => 'blog_post',
        'post_mime_type' => '',
        'post_parent' => '',
        'author' => '',
        'author_name' => '',
        'post_status' => 'publish',
        'suppress_filters' => true
    ];

    $posts = get_posts($args);
    print_r(renderView($posts)); //функция кастомная, отвечающая за вывод загруженных постов в HTML
    wp_die();
}

function renderView($posts)
{
    $view = '';
    foreach ($posts as $post) {
        $postMeta = get_post_meta($post->ID);
        $timeToRead = $postMeta['time_to_read'][0];
        $image_src = wp_get_attachment_image_src(get_post_thumbnail_id($post->ID), 'single-post-thumbnail');
        $single_post = '
            <div class=" vc_col-lg-4 vc_col-md-4 vc_col-sm-6 vc_col-xs-12 blog-post-masonry masonry-block post-offset norebro-card-wrapper grid-item" data-lazy-item="true">
                <div class="blog-grid grid-1 boxed">
                    <header>
                        <a href="https://studiosoftware.com/blog/billing-model-choose-company-discuss-fp-tm-fbsc/">
                            <img src="' . $image_src[0] . '" alt="' . null . '">
                        </a>
                        ' . getPostTags($post) . '
                    </header>
    
                    <div class="content">
                        <h3>
                            <a href="https://studiosoftware.com/blog/' . $post->post_name . '/">
                                ' . $post->post_title . '			
                             </a>
                        </h3>
                        <p>
                            ' . getPostPreview($post) . '…		
                        </p>
                    </div>
                    
                    <footer>
                        <span class="data">' . getPostDateTime($post) . '</span>
                        <strong>—</strong>
                        <span class="data">' . $timeToRead . ' min. to read</span>
                    </footer>
                </div>
                <div class="clear"></div>
            </div>
        ';

        $view .= $single_post;

    }

    return ' <div class="norebro-masonry" data-lazy-container="true" style="position: relative;">' . $view . '</div>';
}

I wrote it according to the documentation from the VP website. At the same time, the paginator does not work periodically, and the following error appears in the console

POST https://my-site.com/wp-admin/admin-ajax.php 400()

Answer 1

The solution to the problem turned out to be ridiculously banal. Since Ajax requests in the VI go to admin-ajax.php, respectively, the WordPress firewall (or whatever is responsible for security) allows only authorized users to send requests to the server. In order for unauthorized users to send requests to the server, one more hook should be connected:
and then requests are sent without problems