I had the Facebook app after the latest update. I had it set to manual refresh. The only time it will self-start is when I get an inbox or an event invite on Facebook. I think this is because Facebook is attached to my Messenger app so if I receive an inbox, FB starts with it. I know when I had a widget on a homepage, FB would just self start on its own, so I had to get that removed. Once FB is on, it is a battery hog even if it isn't updating. I've had to remove the app and do the shortcut/bookmark method as well.