Location based Captive portal is triggered off the incorrect location criteria
Captive Portal users in a location based design are hitting the wrong portal.
Extreme Management Center
The location based portals will look at incoming IP address if configured, as opposed to the ordinary location based criteria (Switch IP, SSID, etc)
Disable the subnet range, or configure them for absolutely no overlap or duplication. Removing the Incoming IP range may present an error, but if the rest of the location based criteria is available, the client will be sent back information from the correct portal.