I have deployed IAP in 2 floors of our building. On the 16th floor, mac/apple devices can connect properly with the captive portal. However, when they go to the 15th floor, they will be reconnected to the network but will be prompted with a WEP password instead of the captive portal username and password sign in page. I'm running Aruba Instant OS 8.5 on an Aruba IAP 303. What is the possible cause of this problem? Is there any configuration that I missed?