While you're at it, check and double check your port forwarding settings. I got bit by this recently.
My owned router had the right ports opened, but the AT&T bridged router did not. Be sure you open ports on both sets of routers, otherwise your owned router will never have a chance to allow the traffic in the first place.
(I just did the same setup with PiVPN. Somehow I got a wrong port number first, but then it worked)