Smart Hub 2 - spurious firewall rules being added

[JT75]

On my BT Smart Hub 2, I am seeing that 2 rules have been added (1 for UDP and 1 for TCP) to open port 6888 in the firewall settings for one client.

The client (192.168.1.223) is my Windows 10 laptop. This behaviour is specific to my device as others in the house do not cause this behaviour. 
I can delete the rules but then they re-appear after a while. Can anyone shed any light on this?

These are the entries created in the Hub's log :-

14:17:41, 09 Jul.
Port forwarding rule added via UPnP/TR064. Protocol: UDP, external ports: any->6888, internal ports: 6888, internal client: 192.168.1.223

14:17:41, 09 Jul.
Port forwarding rule added via UPnP/TR064. Protocol: TCP, external ports: any->6888, internal ports: 6888, internal client: 192.168.1.223

Thanks.

[licquorice]

Tun off UPnP

[Keith_Beddoe]

@JT75 

An application running on a device which has the IP address of 192.168.1.223 is opening the port by using UPnP. If you cannot identify the application or the reason for it, then disable UPnP on the Smart Hub 2.

[JT75]

Thanks for the reply. As I am running a UPnP music server on a Synology NAS on my home network this is not an option but the NAS's firewall does not accept inbound connections. I'll have to try and identify what's causing the rule to be created. 

I've attached a picture of the SH2's firewall settings - could I change the external port number to a 'safe' value?

Thanks

[licquorice]

What is a ' safe value', a port is a port and you can't change it anyway. 

You either accept what is happening or disable UPnP