In addition, refer to this previous post.
As I mentioned there, there are things which will cause this not to work (including being joined to a domain or certain policies being managed by an organization).
However, I just tested with my Windows 11 Pro test server and it worked as expected; that is, with Plex configured to start on login and this setting enabled, Plex Media Server on this system was available after a restart, without logging in.
Note: The system on which I tested uses a Microsoft account for login; I’m not sure if a local account would change the behavior. It’s also an Administrator account.
