Success Message not Displaying

I have a stateless form that I am trying to embed into my website. It works great, with the one exception I can't seem to get the success message to display. When I submit the data, it just resets the form with no indication that it was successful as opposed to just reseting the form. I've also tried a link in the next url field, but that doesn't work either.

Any help or suggestions? Any other information you might need?

Thanks!