Version 1.8.1.4139 not auto updating the library even with this function turned on

Hi all. I am running version 1.8.1.4139 which I understand is the latest version available for the Plex Web Server and am a Plex Pass holder. However, since updating this this version, Plex is not auto updating the libraries when I either add or remove content to the relevant directories. Ive checked my settings and what needs to be on is on but to no avail. I must manually run a reach for the library in order for Plex to show the new content to reflect that I may have removed content…HELP!!!