CF7 doesn’t recognize “required” field inserted via shorttag

Hello,

I’m using two CF7 forms on my site and inserted a “acceptance checkbox” validation with a link because of consistency. This works so far.

To do this I’ve created a shortcode tag “cb” with the desired content:

function dab_cb_form_tag_handler( $tag ) {
    
    $link_dataprotection = get_privacy_policy_url();
    $html_result = Html::div()
        ->content(
            '<div></div>' .
            '<div>' .
            '[acceptance cb-datenschutz]Ja, ich habe die <a href="' . $link_dataprotection . '">Datenschutzerkl?rung</a> zur Kenntnis genommen.<span class="required">*</span>[/acceptance]' .
             Html::p()->content('Ich stimme zu, dass meine Angaben und Daten zur Beantwortung meiner Anfrage elektronisch erhoben und gespeichert werden.</p>') .
             '</div>'
            )
        ->get();
    $formTagsManager = WPCF7_FormTagsManager::get_instance();        
    return $formTagsManager->replace_all( $html_result );
}
  
function custom_add_form_tag_clock() {
    wpcf7_add_form_tag( 
        'cb', 
        'dab_cb_form_tag_handler' 
    );
}
add_action( 'wpcf7_init', 'custom_add_form_tag_clock' );

Problem is now, that CF7 doesn’t recognice the required field – here set with the “acceptance” attribute.
Of course I have activated “acceptance_as_validation: on” in the form settings.

Would be great someone could help to make this run.

Juergen