Cannot log in to app

I have been attempting to log into the Xfinity app for several hours now. I am trying to set up a new modem to start my Internet service in my new residence. Every time I open the Xfinity app, it pulls me up to the sign in page when I click sign in and then brings me to another pop-up where I enter my account information. after I enter my information, it brings me right back to the Xfinity app where it says to sign in. It has been an endless loop. I have quit, deleted, and re-downloaded the app multiple times. I have also cleared my website, data and fixed my cookie settings on safari.  I have had an Xfinity account for the past couple years but have never run into this issue.