I have my Plex on a NAT network, no public IP, but it's port forwarded for direct access with iptables rules and I also use haproxy and cloudflare for the frontend on a subdomain. It is probably as you suggested a networking setup thing. Nothing wrong with my Plex server, running solid for years now. Once I reset the IPtables, it was just like any other VPS and I was able to use v2ray I found about the iptables issue from the oracle cloud thread at OGF. I dont use oracle cloud myself for plex but I do know that firewall configuration alone isnt enough to access services on oracle cloud. The issue in OP's case was due to iptables. Log in to the Plex Media Server application on the machine operating as your server. I have few servers in EU that are accessible whenever I try. There must be sonething wrong with your plex server then or may be network it is on. I get that message appear occasionally even though my Plex is completely accessible. Sometimes Plex lies about whether it can be accessed from the Internet. with nearly 600 manufacturers now running Plex programs in approximately. tried everything and it now works, now gotta figure out which was the key. Plex Systems, a cloud ERP for manufacturers which has its headquarters in Troy.

Running plex in the cloud