Cloned WYSIWYG do not work (no edit/save)

Hello people!

I have a WordPress 4.8.3 installation with Metabox 4.12.4. If I want to clone a WYSIWYG field all the cloned fields are not editable. If I check the code via web developer tool all of them has the same ID. When I save the page all the cloned fields are gone. But if I clone another field, a text field for example, they get different IDs and are saved properly.

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

    $meta_boxes[] = array(
        'id' => 'morecontent',
        'title' => esc_html__( 'Weiterer Inhalt', 'theme' ),
        'post_types' => array( 'post', 'page' ),
        'context' => 'advanced',
        'priority' => 'default',
        'autosave' => false,
        'fields' => array(
            array(
                'id' => $prefix . 'text_1',
                'type' => 'text',
                'name' => esc_html__( 'Text', 'theme' ),
                'clone' => true,
                'sort_clone' => true,
            ),
            array(
                'id' => $prefix . 'inhalt_1',
                'type' => 'wysiwyg',
                'name' => esc_html__( 'Inhalt', 'theme' ),
                'clone' => true,
                'sort_clone' => true,
            ),
        ),
    );

    return $meta_boxes;
}
add_filter( 'rwmb_meta_boxes', 'custom_meta_boxes' );

I also checked it in a fresh and new WP installation. Won't work either.