Port Forwarding Via the Xfinity App does not actually open ports

I have tried every solution online to get some ports open in order to host a server locally on my desktop PC to play a game with a friend.  This has worked for us in the past ~ 6 months ago flawlessley.

Now, when I try and use the Xfinity app to open the ports, they show as being forwarded correctly for the desktop pc, but when I use an online tool to check if they are open, they report back as being closed.

I have updated the app, and added/removed the ports that I need forwarded upwards of 10 times. 

I have logged into the gateway where I used to access port forwarding, but this now just directs the user to download the Xfinity app.

I have spent 3-4 hours in the past few days on the phone with customer support who tell me their backend tools don't allow them to remotely open the ports for me.

As of now there is no solution to actually get these ports to open. The Xfinity app says they're forwarded, but they aren't.

EDIT: Naturally I have tried basic troubleshooting - hard rebooting everything / power cycling / reinstalling app / factory resetting modem.