Help & troubleshooting for channels on your Roku device, including adding/removing channels, logging in to, authenticating, or activating a channel, channel-specific playback issues, assistance contacting channel publishers to report issues, and adjusting channel-specific settings.
I used the xfinity.com/activate link as opposed to xfinity.com/authorize and it finally worked! I was able bypass the error to get to the terms of activation page. Proceeded as normal and all is well after several days and hours spent with Xfinity and no resolution. Not sure if this is the fix, but thought I'd share.