Using the shortcode

Alrighty, should be a simple one, I have the following going on to get relationships:

add_action( 'mb_relationships_init', function () {
    MB_Relationships_API::register( array(
        'id'   => 'cat_to_cat',
        'from' => array(
            'object_type' => 'term',
            'taxonomy'    => 'product_cat',
        ),
        'to'   => array(
            'object_type' => 'term',
            'taxonomy'    => 'product_cat',
        ),
    ) );
} );

Having chosen the from/to in the product category like this:

And then on a new page i have the short code like this:

[mb_relationships id="cat_to_cat" direction="from" mode="ul"]

But it does not display anything? Do i need to list the " items="90924" " in the shortcode or do i need to do this via php? End goal is to get a category list going like this:

Thank you!