ARC and Telstra Smart Modem Gen 2

Telstra (Australia) Smart Modem Gen 2, WiFi, ExpressVPN Present but not active.

Description of Issue:

Getting the ‘Roon ARC was unable to securely access your Roon Core’ message.

Here’s the error message:

Here’s the overview of router settings:

And here’s the specific UPnP page.

I’m hoping this will be trivial for someone with a knowledge of networking to troubleshoot.

It looks like you might be getting a CGNat connection from your ISP. I would double check with them if that is the case. And, if so, see if you can get a static ip.