Not trying to be too salty here because I really do appreciate the amount of work it takes to figure these problems out, but I feel like as the customer in this situation, it should fall on Comcasts shoulders to figure out the issue that's between them and whatever servers they are having trouble connecting to.
The service I use is only having issues with Comcast. Other players with other ISPs (with whom I'm personally in contact with) are not having any issues whatsoever. It sounds like the first reply from the other customer has a little more information than I have as I'm only "okay" at solving networking issue but am by no means a networking professional, rather just a customer of Comcasts