Hi @Daxterous,
Sorry for the delay here. I’m noticing you have a Fritz!Box in your setup. Who is your internet service provider?
Note that we have a step-by-step guide for manually configuring (most) Frizt!Box units here: Port Forwarding Instructions for (Most) Fritz!Box Users - #3 by Philipp_Schaefer
Fritz!Box is a common internet service provider-supplied gateway among providers who have implemented carrier-grade NAT (CG-NAT). Please also review this list of known carriers who have CG-NAT in such a way that it requires additional workarounds: ISPs and Routers: List of Known Solutions and Workarounds