After a very dissapointing customer service chat today I can say for sure that Xfinity has no idea what they are doing.
The port forwarding feature on xFi is hopeless and needs to be fixed.
I've read many posts about it on this forum with no hope of resolving the issue.
IPv6 is disabled
xFi advanced security is diabled
Port checkers always reporting ports as closed.
Checking the connections manually, also closed.
The companies need to give control back to the users. This is rediculous.