@David-TP  Thanks for the offer of escalated support which I would have gladly taken up at another time but I am extremely busy with limited spare time right now.

I tried for a whole day to get the Nord product to work and spent over an hour chatting with one of their tech support guys.  Made no progress so cancelled.  I have just tried Proton instead and it worked straight away.

I used the a wireguard config file with the Proton subscription and it was dead easy.  With Nord I was using OpenVPN config file (they don't appear to provide wireguard config files and have their own version called NordLynx?).  Maybe I'm wrong but that's the impression I got.

So in conclusion it wasn't a router firmware issue and it wasn't an obvious schoolboy error on my part (I had followed all the steps correctly).  The issue will most likely have been somewhere in the text of the config file itself but I had no capacity for throwing even more time at it unfortunately.

Now that I have successfully configured VPN client on my X50 I can confirm that creating country/server specific config files is a breeze but the one thing I think you could consider doing that would be an enormous improvement in the app would be making the connected status of the VPN client more visible please.

At the moment I have to go into the Deco app then navigate More>VPN>VPN Client to see the "Connected" status of the client.  If there was a status indicator on the main Network page or perhaps a notification alert if the VPN connection is lost that would be brilliant.

This would not be a concern for me if the devices added to the protected list were dis-connected from the internet whenever VPN connection is lost but I think instead the devices default back to the un-protected normal IP address potentially compromising their security.  I guess auto-disconnection would make more sense as then no security is compromised and I can then choose how and when to re-connect the devices.

Thanks again.