I have tried every avenue of support to resolve this and the closest I got was a tier 2 phone tech support agent who did not know what an ip address was and when he passed on my request to talk to an actual XFinity support agent was told no, they would not speak to me.
I have intermittent connection failures with my banks web site, they say there is no problem on their end. I can access the site via 4G LTE while the Xfinity internet connection still reports errors. So it looks like the bad old days of Comcast support might be remembered as a golden age compared to the no support days of Xfinity. At this point my only remaining options appears to be looking for a new provider.
@charlesryan1 I am sending you a PM to gather more info.