Vim + vimwiki is what I use, with session saving plugin. That is all I need. For syncing, I use either git or syncthing.

Can you access your wan ip when you are somewhere else than on your own lan?

If not, then this is probably just that your router does firewalling and nat is such order that you can access admin interface from local network via wan address.

If yes, then router has some serious misconfiguration.

Wagnerians in Lipetsk, avout 300 km from Moscow

https://canada.unofficialbird.com/nexta_tv/status/1672602398915809282#m