New Plex Server / Remote access

I think you should first verify that your server is remotely accessible before inviting people.
It appears you have scrapped your server yet again. And it hasn’t been made accessible remotely yet. The Basics of Remote Access Troubleshooting

Don’t expect a newly created server to be available instantly. It first needs to get a subdomain, which then needs to propagate across the DNS system, before remote users can contact your server.