In order for you to complete the setup of the surfboard central app, G36 should have internet connection. When you attempt to access the web-based interface (GUI), if it prompts you for an email address and password, it means the credentials are managed through the Surfboard Central app. However, if the app hasn't been set up correctly, the GUI page may not function as expected, leading to a misconfiguration. In this case, neither the app setup will complete nor will you be able to access the GUI.
Note: The Surfboard Central app syncs with the GUI during the initial setup process. If you access the GUI first before setting up the app, it will prompt you to create a password for accessing the web interface.
Currently, since both the app setup and GUI access are not working, we recommend performing a factory reset on the G34.
After performing the factory reset, we recommend setting up the Surfboard Central app first. Please find the link below for the app setup instructions:
http://arris.force.com/consumers/articles/knowledge/SURFboard-Central-Wi-Fi-Cable-Modem-Setup