Global variable and displaying text in checkout

I’m using some modified code shared by someone else in this forum (below).

function md_custom_woocommerce_checkout_fields( $fields )
{
global $html;
$fields[‘order’][‘order_comments’][‘placeholder’] = ‘Special notes’;
$fields[‘order’][‘order_comments’][‘label’] = ‘Add your special note’;
$html=’mynote’;
return $fields;
}
add_filter( ‘woocommerce_checkout_fields’, ‘md_custom_woocommerce_checkout_fields’ );

Next I want to display the $html:

add_action(‘woocommerce_checkout_after_terms_and_conditions’, ‘add_terms_and_policy’, 20);
function add_terms_and_policy() {
global $html;
echo $html;
}

The problem is that I can see mynote displayed for a second and then it disappears. So I’m so close to solving a problem. Does anyone know why it would then hide?