HTML Type pattern=”d{3}-d{3}-d{3}

Unfortunately also not working (same error-message / red field) – please can you show an example of how it works in the graphical UI?
As no pictures are possible to add, I can not show the result – only describe it…
I am doing it in “Taxonomies = category”.

Copde generated:

<?php
add_filter( 'rwmb_meta_boxes', 'your_prefix_register_meta_boxes' );

function your_prefix_register_meta_boxes( $meta_boxes ) {
    $prefix = '';

    $meta_boxes[] = [
        'title'      => esc_html__( 'Category_Order', 'text-domain' ),
        'id'         => 'Category_order',
        'fields'     => [
            [
                'id'            => $prefix . 'M_category-orderID',
                'type'          => 'number',
                'name'          => esc_html__( 'Category Order ID', 'text-domain' ),
                'required'      => 1,
                'tooltip'       => 'defines order priority',
                'admin_columns' => [
                    'position' => 'before name',
                    'sort'     => true,
                ],
            ],
            [
                'id'      => $prefix . 'text_sb532j9yqc',
                'type'    => 'text',
                'name'    => esc_html__( 'Text Field', 'text-domain' ),
                'pattern' => '[0-9]{3}-[0-9]{3}-[0-9]{3}',
            ],
        ],
        'taxonomies' => ['category'],
    ];

    return $meta_boxes;
}