Troubleshooting: Customers seeing general receipt page instead of custom HTML sent with Relay Response post
This is a very common problem. If customers are sent to a page with the general receipt layout instead of the customized HTML sent via Relay Response you have likely not set the x_relay_response property correctly, or included the following line altogether:
name="x_relay_response" value="True"
Once this line of code is included Relay Response should work correctly.