My form will not redirect properly after submit

My forms within my pages have the action to redirect to a /thanks.html page.

When the form is submitted, the URL in the bar changes appropriately but page just shows the default netlify confirmation.

“form name=“contact-us-modal” action=”/thanks.html" method=“POST” class=“email-form” data-netlify=“true”>" is an example of one of the form tags

Is there a file called thanks.html as part of the site deploy?

Can you share the name of the site in question?

Have you looked through