UPNP stopped working

I'm Samy an independent advisor and I'll be helping you

Clean your console's MAC and restart your internet devices.
Network Settings> Advanced Settings> MAC Address

How are you?

If the problem persists I recommend calling your ISP and asking to open these ports.

Port 88 (UDP)
Port 3074 (UDP and TCP)
Port 53 (UDP and TCP)
Port 80 (TCP)
Port 500 (UDP)
Port 3544 (UDP)
Port 4500 (UDP)

Also ask to put the IP of the console in the DMZ zone, if you need additional ports this function will take care of that.

Here is some trouble shooting steps to try.

Sign in to your router’s setup webpage, and make sure the router’s UPnP setting is turned on. You can usually find first-time help with this in the router manual or on the manufacturer’s support site.

Turn the UPnP setting off and save your changes.

Restart your console, your modem, and your router.

Turn the UPnP setting back on and save your changes. If there’s a Zero Config setting, make sure that’s turned on as well.

Restart your modem and router.

Once you’ve reset your router:

Restart your console.

Press the Xbox button to open the guide.

Select System > Settings > General > Network settings.

Check your settings again to make sure the UPnP message is gone.

Hope this helps I have an R8000 and havent had any issues with the UPnP. I do have to some power cycles on my network equipment from time to time.

I'm Samy an independent advisor. Welcome to the Xbox community. How are you?

Clean your console's MAC and restart your internet devices.
Network Settings> Advanced Settings> Alternate MAC address and Clear.

If the problem persists this may be because your ISP is limiting or blocking the ports that Live needs to function properly. I recommend calling your ISP and asking to open these ports.

Port 88 (UDP)
Port 3074 (UDP and TCP)
Port 53 (UDP and TCP)
Port 80 (TCP)
Port 500 (UDP)
Port 3544 (UDP)
Port 4500 (UDP)

Also ask to put the IP of the console in the DMZ zone, if you need additional ports this function will take care of that.

Well

You need to open doors for xbox, some router do automatically but other you need to do by manual.

https://beta.support.xbox.com/help/Hardware-Network/connect-network/network-ports-used-xbox-live

And you can check for more doors. Because some games need an adicional door.

Good to hear it is sorted.

As alternate thing, be sure to check if there is any firmware update available for the router itself and if that fixes any issues etc.

Also be sure to search for reviews for the updates, to prevent any bad surprises