Hi,

I'm trying to configure what's usually called port forwarding (at least in my experience with other devices) & have tried to cnfigure my new Archer NX210 settings, using NAT Forwarding & Virtual Servers.

I've added the ports I need open (80, 81, 443, 8080) & pointed them all to the target internal device on 192.168.1.4 (which is the IP address of my Raspberry Pi 5 16GB running Ununtu Server 25.04

I've run this setup many time at home, using my home router, & it simply works well.

I'm away from home & have bought the Archer NX210 to connect to the Internet using a 5G SIM, which is owrking fine for general internet access.

However, I can see my exteranl IP address (31.94.xxx.xxx using whatsmyip) is different to that displayed in the NX210 Admin page: Advanced -> Status & scrolling dwn to the Internet section shows a completely different IP address: 100.69.xxx.xxx

FYI, my use case, is that I'm trying to use Nginx Proxy Manager on my Raspberry Pi to generate an SSL certificate for my site app. But unfortunately it returns the following error: "There is a server found at this domain but it returned an unexpected status code Invalid domain or IP. Is it the NPM server? Please make sure your domain points to the IP where your NPM instance is running".

I've tried various firewall related reconfigs on my Raspberry Pi, but nothing's worked & I've sucessfully had this working on my home router & suspect the NX210 may be doing some alternative IP routing (over the mobile network?) in the background that is outside of my realm of knowledge.

I'd appreciate it if someone could please explain what's going (in simple terms :-) & Ideally how this can be resolved.

Cheers!