Conditional Logic doesn't work inside group field

Hello,

I wish to have a conditional logic inside a group field but it doesn't work.

So I take the basic example in your docs and put it inside a group field.
The logic does not seem to work here either. Or do I something wrong?

add_filter( 'rwmb_meta_boxes', function( $meta_boxes ) {
    $meta_boxes[] = array(
        
        'title' => 'Brands and Products',
        'post_types' => ['page'],
        'context' => 'side',
        
        'fields' => array(
            array(
                'id' => 'test_group',
                'type' => 'group',
                'fields' => array(
                    array(
                        'id'    => 'brand',
                        'name'  => 'Brand',
                        'desc'  => 'Pick Your Favourite Brand',
                        'type'  => 'select',
                        'options' => array(
                            'Apple'         => 'Apple',
                            'Google'        => 'Google',
                            'Microsoft'     => 'Microsoft'
                        )
                    ),
                    array(
                        'id'    => 'apple_products',
                        'name'  => 'Which Apple product that you love?',
                        'type'  => 'radio',
                        'options' => array(
                            'iPhone'    => 'iPhone',
                            'iPad'      => 'iPad',
                            'Macbook'   => 'Macbook',
                            'iWatch'    => 'iWatch'
                        ),

                        // Hide this field when user selected a brand that's not 'Apple'
                        'hidden' => array( 'brand', '!=', 'Apple' )
                    )
                )
            )
        )
    );

    return $meta_boxes;
} );

Thanks for your help
Jürgen