Access Denied You don't have permission to acces

Intermittently and sometimes for hours I receive  "Access denied" when attempting to sign into my Xfinity account using a web browser.  Yes, I have cleared all caches; reset the modem; and restarted the computer. I have full access to the Internet except for Xfinity. Yet, "Access" is "denied". (I cannot post on this Forum when the issue is present because I cannot sign in. Catch-22.) This must be a known issue to Xfinity. Xfinity does not have a "script" that meaningfully addresses the issue. The "script" is just an "IT Crowd" TV-show "script." The person reading the "script" is as useless as automated support.

Access Denied
You don't have permission to access "http://login.xfinity.com/login" on this server.
[Edited: "Personal Information"]
[Edited: "Invalid Link"]