I had the same problem. I was no longer able to remotely access my q-see outdoor cameras. The problem is caused by the router used for the xfinity home security. They install the modem directly to the router for the security system and then connect your home router to the security router. This router can not be accessed to allow port forwarding. You will find the default user name and password has been altered. You will need to place your home router directly into your modem. Connect the Home Security router to your home router. Be sure to use high speed ethernet cables for all these connections. Failure to use high speed cables will result in your camera not working. Reboot your touch screen panel and that should be it. If this doesnt work reboot your modem let give it a minute then reboot your router give it a minute then finally reboot your Home Security router.
I have had no issues with this configuration!