Thank you, I will try there, I was trying to install PiVPN since I can connect to the Gogs server on my local network, if I could just get a VPN server running it should work, but of course more issues with that. The cause could well be some config I might have changed and forgotten about, reimaging and starting fresh might be the easiest solution.
Though, I did just upgrade to FTTP - which added a modem or some kind of device between my router and the internet, so maybe there could be some extra config surrounding that I’m just not aware of