Can't open any cox pages via wi-fi using Motorola SGB6580

We recently purchased a Motorola SGB6580 modem/router combo and are unable to load any cox pages or connect to cox webmail using a wireless connection on the laptop or on the phone. We are able to open all other pages with no problem on the wireless connection. We can open cox pages on the computer when it is hardwired to the modem and on the phone when it is disconnected from the wi-fi connection. The problem is only related to cox pages when using the wi-fi connection. Is there a fix for this issue?