Can't login to xfinity app - Endless loop

Hello,

I can login under my Comcast account, but when I press "Continue" it goes back to the screen requesting my sign in.  Can you please tell me how to bypass this endless loop so I can set up my Comcast pods?  Why would it tell me I'm already logged in but then ask me to sign in again?  Please help asap -- we need this immediately for a project  Thanks.