The Frustrating Facebook Notification bug.

I bet that I'm not the only one who suffers this issue with iOS. For some reason, Facebook only decides to send push notifications for completely random notifications without any consistency. It only pushes on a select few posts. I do not get a push for, wall posts, messages and loads of other stuff. It is as if the app only does it when it feels like it. Has anyone had this problem? Does anyone know a fix? I've checked and re-checked all the settings within iOS and the Facebook app, yet I cannot find a solution. Thanks in advance.