Issue with checkout template (Woocommerce -> Checkout -> form-checkout.php)

Hi,

Can you please advise why when I create a new custom checkout in child theme under: Woocommerce -> Checkout -> form-checkout.php it has no effect?

In Xstore theme options -> checkout; the advanced switch is turned off. So it should essentially render the default form-checkout.php file or at worst, the form-checkout-default.php file but whenever I create a custom checkout, nothing changes.

Are you overriding even the default checkout style? If not, based on the default settings with advanced checkout toggle set to off – what template do I need to use to create my override?

Even testing editing the primary files with a simple check command, nothing occurs front-end?

<?php
echo '<div style="background:red; color:#fff; padding:10px;">CHILD THEME CHECKOUT TEMPLATE ACTIVE</div>';

Thanks