Nicolas,
I have this url in the Return URL of the Authorize Payment Plugin:
https://divorcetoolbox.net/thank-you-for-your-purchase
When I click the checkout submit button and I stop it on the page that has the "Please wait while you are redirected to Authorize
If you are not redirected after 10 seconds, please click on the button below.", it has this hidden field in this form:
<form id="hikashop_authorize_form" method="post" action="https://secure.authorize.net/gateway/transact.dll" name="hikashop_authorize_form">
Hidden Relay URL field:<input type="hidden" value="https://www.divorcetoolbox.net/index.php?option=com_hikashop&ctrl=checkout&task=notify¬if_payment=authorize&tmpl=component&lang=en&Itemid=355" name="x_relay_url">
There are NO other fields that have a URL in them at all.
Here is the Authorize plugin settings at the time that I did this test.
Now can you explain how the proper relay field is NOT included in the transaction?