(sorry for the french screenshot but I believe it’s still understandable)
Use case:
I have a VPN. It force all the outgoing traffic through the VPN (shame I can’t do split tunneling). Therefore when enabling remote access the public IP detected is the one from the VPN. I would like the public IP to be my public IP (for better performances but also cause I can’t control PAT on the VPN side)
You used https You can’t do that unless you also have a fitting, publicly trusted certificate. Which is not easy to get, since this is not a FQDN but an IP address.
Try with http instead.
Restart Plex server after putting it in.
Leave it sitting there for at least a few hours.
Then reboot one of your clients and try to reach your server from the outside.
Ignore the message about remote availability in Plex, because the accessibility test doesn’t work with a custom URL.