Hi Hernan,
You need to define the post_types
setting when registering the meta box. For example:
add_filter( 'rwmb_meta_boxes', 'prefix_register_meta_boxes' );
function prefix_register_meta_boxes( $meta_boxes ) {
$meta_boxes[] = [
'title' => 'Personal Information',
'post_types' => 'post-type-slug', //here
'id' => 'my-meta-box',
'fields' => [
...
]
];
return $meta_boxes;
}
Read more on the documentation https://docs.metabox.io/creating-meta-boxes/#field-group-settings