@Ronin_Ng PMS 1.1.0 introduced the following functionality: When server is signed in, clients must be signed in as well, even if they are on the LAN or on localhost. This created problems in a number of Plex clients. PMS 1.1.1 and 1.1.2 tried to fix the problem.
But PlexConnect supports ATV login, therefore it’s possible that you can solve your problem using this capability.