Funnily enough I saw this earlier, I logged the server out of my account and all clients on the network could see all libraries regardless of whether they entered the password.
I definitely don’t have the “allow without auth” option selected, I was very surprised to see this on the client.
If you take the server out of your plex account, all clients on the local network can access it without authentication. This is very normal and intended.
This server is not in local network, as mentioned earlier accessing media remotely,
i think some security issue is their which is allowing clients to access media without authorization, check backed logs for this post hopefully you will be able to identify root cause.another security issue