Hello shannoncrow

                                  You can try uninstalling and re installing app and perform hard reset on the modem for 30secs without the cox cable on it, this will fix the issue if not you can try using different email address to login to the surfboard central application. But after resetting the modem will go to default setup any custom settings will be removed so use the default network name and password to connect to your network. Please follow the steps mentioned on the below link to reset modem.

                                 http://arris.force.com/consumers/articles/General_FAQs/SBG7400AC2-Factory-Reset