Custom Taxonomy archive returns 404

Question

I made custom post type with one taxonomy. Everything was good except pagination on taxonomy. Firstly, without any changes, I was able to switch pages on main custom post type archive:

website.com/custom_post_type_name/page/x

But when I wanted to jump to taxonomy and switch pages I got 404 error.

website.com/custom_post_type_name/taxonomy_slug/page/x

I tried doing regex from answer from StackExchange but it won't work at all.

add_filter( 'rewrite_rules_array', 'my_insert_rewrite_rules' );
function my_insert_rewrite_rules( $rules ) {
  $newrules = array();
  $newrules['promocje(/[a-z]+)(/page/([0-9]+))?'] =
      'index.php?post_type=promocje'
      . '&shop=$matches[1]&paged=$matches[3]';

  return $newrules + $rules;
}

• promocje is the name of the post type.
• shop is the name of the taxonomy.

After that, I was able to switch pages on taxonomy pages, but I had 404 error when paginating the custom post type.

Code of custom post type and taxonomy:

    $args = array(
        'labels' => $labels,
        'hierarchical' => false,
        'description' => 'Promocje filtrowane przez sklep',
        'supports' => array( 'title', 'editor', 'author', 'thumbnail', 'trackbacks', 'custom-fields', 'comments', 'page-attributes' ),
        'taxonomies' => array( 'shop'),
        'public' => true,
        'show_ui' => true,
        'show_in_menu' => true,
        'menu_position' => 5,
        'menu_icon' => 'dashicons-format-audio',
        'show_in_nav_menus' => true,
        'publicly_queryable' => true,
        'exclude_from_search' => false,
        'query_var' => true,
        'can_export' => true,
        'capability_type' => 'post',
        'register_meta_box_cb' => 'add_promo_metaboxes',
        'rewrite' => array( 'slug' => 'promocje/%shop%', 'with_front' => false ),
        'has_archive' => 'promocje',
    );
    function wpa_show_permalinks( $post_link, $post ){
    if ( is_object( $post ) && $post->post_type == 'promocje' ){
        $terms = wp_get_object_terms( $post->ID, 'shop' );
        if( $terms ){
            return str_replace( '%shop%' , $terms[0]->slug , $post_link);
        }
    }
    return $post_link;
}
add_filter( 'post_type_link', 'wpa_show_permalinks', 1, 2 );

And taxonomy:

register_taxonomy(
    'shop',
    'promocje',
    array(
        'hierarchical' => true,
        'label' => 'Sklep',
        'query_var' => true,
        'rewrite' => array(
            'slug' => 'promocje',
            'with_front' => false
        )
    )
);

Any help would be appreciated. I've been trying to solve this for more than a week.

Answer 1

From the Admin Dashboard, Go to Permalink Settings and hit Save Changes. Hope this will solve the problem.

Answer 2

I solved it! You need to var_dump wp_query on 1st page and on 404 page

add_action( 'pre_get_posts', 'elo_jlb' );
function elo_jlb($query)
{
    if(!is_admin())
    {
        $query->set('paged', $query->get('page'));
        $query->set('HERE_POST_TYPE_NAME', '');
    }
}