Cannot navigate to any comcast.net inbox

I'm trying to access my comcast.net email. Every time I click "Check Email" under the Account right-nav, it takes me to this page: https://www.xfinity.com/support/articles/how-to-access-email-account. There is an ongoing circular loop without actually taking me to my inbox. I know comcast.net emails are migrating to Yahoo!, but mine isn't active there.