Meta Box

More info...

In version 5.6.4:

line 44 of file metabox/js/select-advanced.js :

text: item.label,

In version 5.6.7:

line 44 of file metabox/js/select-advanced.js :

text: _.unescape( item.label ),

If I manually delete "_.unescape" it works again.

OMG... these fields are disabled in the screen options (at the top).

It works now, sorry for the inconvenience.

Here you are (from Button "get php code" of the builder):

This is a CPT:

<?php
add_action( 'init', 'your_prefix_register_post_type' );
function your_prefix_register_post_type() {
    $labels = [
        'name'                     => esc_html__( 'Deportes', 'your-textdomain' ),
        'singular_name'            => esc_html__( 'Deportes', 'your-textdomain' ),
        'add_new'                  => esc_html__( 'Añadir nueva', 'your-textdomain' ),
        'add_new_item'             => esc_html__( 'Nueva noticia', 'your-textdomain' ),
        'edit_item'                => esc_html__( 'Editar noticia', 'your-textdomain' ),
        'new_item'                 => esc_html__( 'Nueva noticia', 'your-textdomain' ),
        'view_item'                => esc_html__( 'Ver noticia', 'your-textdomain' ),
        'view_items'               => esc_html__( 'View Deportes', 'your-textdomain' ),
        'search_items'             => esc_html__( 'Search Deportes', 'your-textdomain' ),
        'not_found'                => esc_html__( 'No deportes found', 'your-textdomain' ),
        'not_found_in_trash'       => esc_html__( 'No deportes found in Trash', 'your-textdomain' ),
        'parent_item_colon'        => esc_html__( 'Parent Deportes:', 'your-textdomain' ),
        'all_items'                => esc_html__( 'Noticias', 'your-textdomain' ),
        'archives'                 => esc_html__( 'Deportes Archives', 'your-textdomain' ),
        'attributes'               => esc_html__( 'Deportes Attributes', 'your-textdomain' ),
        'insert_into_item'         => esc_html__( 'Insert into deportes', 'your-textdomain' ),
        'uploaded_to_this_item'    => esc_html__( 'Uploaded to this deportes', 'your-textdomain' ),
        'featured_image'           => esc_html__( 'Featured image', 'your-textdomain' ),
        'set_featured_image'       => esc_html__( 'Imagen destacada', 'your-textdomain' ),
        'remove_featured_image'    => esc_html__( 'Borrar imagen destacada', 'your-textdomain' ),
        'use_featured_image'       => esc_html__( 'Usar como imagen destacada', 'your-textdomain' ),
        'menu_name'                => esc_html__( 'Deportes', 'your-textdomain' ),
        'filter_items_list'        => esc_html__( 'Filter deportes list', 'your-textdomain' ),
        'filter_by_date'           => esc_html__( '', 'your-textdomain' ),
        'items_list_navigation'    => esc_html__( 'Deportes list navigation', 'your-textdomain' ),
        'items_list'               => esc_html__( 'Deportes list', 'your-textdomain' ),
        'item_published'           => esc_html__( 'Deportes published', 'your-textdomain' ),
        'item_published_privately' => esc_html__( 'Deportes published privately', 'your-textdomain' ),
        'item_reverted_to_draft'   => esc_html__( 'Deportes reverted to draft', 'your-textdomain' ),
        'item_scheduled'           => esc_html__( 'Deportes scheduled', 'your-textdomain' ),
        'item_updated'             => esc_html__( 'Deportes updated', 'your-textdomain' ),
    ];
    $args = [
        'label'               => esc_html__( 'Deportes', 'your-textdomain' ),
        'labels'              => $labels,
        'description'         => '',
        'public'              => true,
        'hierarchical'        => false,
        'exclude_from_search' => false,
        'publicly_queryable'  => true,
        'show_ui'             => true,
        'show_in_nav_menus'   => true,
        'show_in_admin_bar'   => true,
        'show_in_rest'        => false,
        'query_var'           => true,
        'can_export'          => true,
        'delete_with_user'    => false,
        'has_archive'         => true,
        'rest_base'           => '',
        'show_in_menu'        => true,
        'menu_position'       => 5,
        'menu_icon'           => 'dashicons-admin-site',
        'capability_type'     => 'post',
        'supports'            => ['title', 'editor', 'thumbnail', 'author'],
        'taxonomies'          => ['c-deportes', 'e-deportes'],
        'rewrite'             => [
            'with_front' => false,
        ],
    ];

register_post_type( 'deportes', $args );
}

This is a taxonomy for the previous CPT:

<?php
add_action( 'init', 'your_prefix_register_taxonomy' );
function your_prefix_register_taxonomy() {
    $labels = [
        'name'                       => esc_html__( 'Categorías', 'your-textdomain' ),
        'singular_name'              => esc_html__( 'Categoría', 'your-textdomain' ),
        'menu_name'                  => esc_html__( 'Categorías', 'your-textdomain' ),
        'search_items'               => esc_html__( 'Search Categorías', 'your-textdomain' ),
        'popular_items'              => esc_html__( 'Popular Categorías', 'your-textdomain' ),
        'all_items'                  => esc_html__( 'All Categorías', 'your-textdomain' ),
        'parent_item'                => esc_html__( 'Parent Categoría', 'your-textdomain' ),
        'parent_item_colon'          => esc_html__( 'Parent Categoría', 'your-textdomain' ),
        'edit_item'                  => esc_html__( 'Editar categoría', 'your-textdomain' ),
        'view_item'                  => esc_html__( 'Ver categoría', 'your-textdomain' ),
        'update_item'                => esc_html__( 'Actualizar categoría', 'your-textdomain' ),
        'add_new_item'               => esc_html__( 'Añadir nueva categoría', 'your-textdomain' ),
        'new_item_name'              => esc_html__( 'New categoría name', 'your-textdomain' ),
        'separate_items_with_commas' => esc_html__( 'Separate categorías with commas', 'your-textdomain' ),
        'add_or_remove_items'        => esc_html__( 'Add or remove categorías', 'your-textdomain' ),
        'choose_from_most_used'      => esc_html__( 'Choose most used categorías', 'your-textdomain' ),
        'not_found'                  => esc_html__( 'No categorías found', 'your-textdomain' ),
        'no_terms'                   => esc_html__( 'No Categorías', 'your-textdomain' ),
        'filter_by_item'             => esc_html__( 'Filter by categoría', 'your-textdomain' ),
        'items_list_navigation'      => esc_html__( 'Categorías list pagination', 'your-textdomain' ),
        'items_list'                 => esc_html__( 'Categorías list', 'your-textdomain' ),
        'most_used'                  => esc_html__( 'Most Used', 'your-textdomain' ),
        'back_to_items'              => esc_html__( 'Back to categorías', 'your-textdomain' ),
    ];
    $args = [
        'label'              => esc_html__( 'Categorías', 'your-textdomain' ),
        'labels'             => $labels,
        'description'        => '',
        'public'             => true,
        'publicly_queryable' => true,
        'hierarchical'       => true,
        'show_ui'            => true,
        'show_in_menu'       => true,
        'show_in_nav_menus'  => true,
        'show_in_rest'       => true,
        'show_tagcloud'      => true,
        'show_in_quick_edit' => true,
        'show_admin_column'  => false,
        'query_var'          => true,
        'sort'               => false,
        'meta_box_cb'        => 'post_tags_meta_box',
        'rest_base'          => '',
        'rewrite'            => [
            'with_front'   => false,
            'hierarchical' => false,
        ],
    ];
    register_taxonomy( 'c-deportes', ['deportes'], $args );
}

Thanks!

Sorry, wrong function. With rwmb_meta instead it's works.

Can delete this topic if you want.