Unable to Sign Into New Xfinity Prepaid Account

Hello.  I just received and installed my new Xfinity Prepaid modem.  I am able to connect to the internet, and everything appears to be working.  However, I cannot log into my Xfinity account at https://www.xfinityprepaid.com/.  When I try to do so, it redirects me to https://my.xfinityprepaid.com/en/account-picker and asks me to select the address associated with the device I want to manage. It does not list any addresses at all but does provide a link to https://customer.xfinity.com/#/settings/account/linked-accounts/ to link addresses.  Clicking that link displays a communication error and sends me back to another login page.  Trying to log in at that page just loops back to the communication error page and then back to the same login page.

Please check my account to see if there something causing it not to be able to fully log in.  It should only be linked to a single address.

Much appreciated,

Jared