Q:

cpt not display inside nav menu

I have created a cpt to realize a dedicated section of a website and I want to show it inside the navigation menù with the various post created under the cpt linked as children. I've noticed that the cpt I've registered isn't recognized,  but other two cpt I have are showed inside the menù editor and I'm able to select them. Is there a fix? 
  /*
  * Post type: Services
  */

  function services()
  {
    $labels = array(
      'name'               => _x( 'Servizi', 'post type general name'),
      'singular_name'      => _x( 'Servizi', 'post type singular name'),
      'menu_name'          => _x( 'Servizi', 'admin menu'),
      'name_admin_bar'     => _x( 'Servizi', 'add new on admin bar'),
      'add_new'            => _x( 'Aggiungi Servizi', 'Aggiungi servizio'),
      'add_new_item'       => __( 'Aggiungi Servizi'),
      'new_item'           => __( 'Aggiungi Servizi'),
      'edit_item'          => __( 'Modifica Servizi'),
      'view_item'          => __( 'Visualizza Servizi'),
      'all_items'          => __( 'Visualizza Tutto'),
      'featured_image'     => __( 'Featured Image', 'text_domain' ),
      'search_items'       => __( 'Cerca Servizio'),
      'parent_item_colon'  => __( 'Parent:'),
      'not_found'          => __( 'No service found.'),
      'not_found_in_trash' => __( 'No service found in Trash.'),
    );

    $args = array(
      'labels'             => $labels,
      #'menu_icon'       => 'dashicons-star-half',
     'description'        => __( 'Description.'),
      'public'             => true,
      'publicly_queryable' => true,
      'show_ui'            => true,
      'show_in_menu'       => true,
      'query_var'          => true,
      'rewrite'            => true,
      'capability_type'    => 'post',
      'has_archive'        => true,
      'hierarchical'       => true,
      'menu_position'      => null,
      'supports'           => array('title','editor','thumbnail','custom-fields','excerpt')
    );

    register_post_type( 'services', $args );
  }
  add_action('init', 'services');

The code I've used for the other two cpt is the same.

A:

Check Screen Options in Menu Editor window, you should have your cpt box checked.

