If you’ve Bridged one of the routers to remove the local double-NAT layer, then please post any updated diagnostic error you see in Roon Settings → ARC.
Who is your internet service provider? It’s possible there’s a CG-NAT layer upstream of your account.
Hi Connor, thanks for the support. I only have one router which is the TP Deco X50-5g. My nucleus one is directly connected to it and the diagnostic above is what I got. This was never an issue with my old DSL router and my ISP so it’s evident that the TP Deco is causing this headache. The TP Deco X50 settings are so basic you can’t change them, I’ll try to post a photo to showcase the 2 IPs.
Since the external IP address is a ten-dot network, and the connection identified as mobile, it looks like you are on CGNAT.
However, you have a couple of options. The ISP may be able to provide a static (public) IP address, or you could use Tailscale. Unfortuntely, using this with a Nucleus, while doable, is not straightforward.
@Martin_Webster is correct in their response above. Let us know if you have any additional questions, and if you’re able to get a static address from your ISP.