Pepwave Mini Captive Portal Page Not Coming Up

We currently have Peplink routers with Pepwave Access Points deployed. Neither the router or the AP have settings deployed via InControl. We have the SSIDs and the Captive Portal page setup on the router. On the router we have the AP added so it can be the controller for the AP. We have the captive portal page configured to go to the default splash page which is “captive-portal.peplink.com”. When trying to connect to the Guest wifi that is configured with the captive portal, it will connect but will have no internet connection. We are able to connect to all the other SSIDs that are being broadcast without the captive portal. Also, we have this same setup at a different location, setup with the exact same settings and it works just fine and will go directly to the splash page, then the landing page once the user accepts the Terms and Conditions. The routers and APs are all running the latest firmware as well. Does anyone have any suggestions as to why this may be happening to one customer setup but not another??