I had the same issue with port forwarding so I turned it off. About a week ago I tried the advanced security again and am now able to access my devices that rely on port forwarding. They must have finally fixed at least that bug in their software. Wold be nice if we could get updates from Xfinity on issues that they are addressing rather than having to figure out things on our own.
Hello and just as EG mentioned you might have to turn off your Advanced Security and turn it back on and or keep it off depending. Please if you still can't get it to work click on my name ComcastJosh and send me your full name and your account number and i will assist you with the port forwarding. Our product develeopement team and our enginners are already aware of some known issues and we are working to resolve them on the backend as well and will be pushed our with new software updates.