How do I add an airport extreme to existing time capsule network and be able to use the router ethernet ports?

Good day everyone. I recently upgraded my airport extreme network by replacing the base station with a time capsule router. Since I now have an "extra" airport extreme router, I've set it up on the other side of the house to both extend the wireless range as well as use it's LAN ports for a home theater system in that location. Connecting the two routers was done via ethernet. It now appears that I need to do something "else" as the LAN ports on the now relocated airport extreme are nonfunctional. All devices are operating well for wireless and as a review, the modem is connected to the time capsule WAN which is connected to the airport extreme via ethernet cable via LAN to it's WAN port. What do I need to change on configurations to get the LAN ports functioning on the airport extreme? Thank you for any help.