Form no longer working on a custom page

Hi

Thank you for a great plugin.

I’m having an issue since the last update that I need help for please:

I run a few websites that are locked down from the public. To allow people access by requesting registration (and approving manually) I’ve been using the contact form 7 on a custom php page where I call <?php require_once('wp-load.php'); ?> and <?php wp_head(); ?>

This has been working perfectly up till the last update. The shortcode still loads the content of the form but when you click submit, the page loads and seems to submit, but it does not return a success or error message (and no loading icon next to the submit button)

Please check out https://www.shophyundai.co.za and click on the”registration request” link below the form to see what I mean.

The page I need help with: [log in to see the link]