In the Routes options of the load-balancer, setting up a Direct Response route makes that response returned with a content-type header set to "text/plain". That makes the web browser show the HTML code of the page instead of the web page.

Prompting the user with one tiny extra drop-down menu to set the content-type of the direct response they’re setting up would be very helpful, especially when their origin server have issues that they’re trying to compensate for leveraging F5XC.