Norton shutting down my connection to connect.xfinity.com because it's flagged as "a dangerous web page"

I can open my xfinity email, and read messages, but I can't do anything with the messages - like delete them or move them to my folders. My Norton keeps giving me this message as I sign in to open my email:

"Threat secured"

"We prevented your coneection to connect.xfinity.com because it is a dangerous webpage. Threat category: URL:Phishing"