Facebook won't automatically update messages?

[Romanceboy]

When you send someone a message, and it says 'Seen' if they are replying, it comes up ".... Is typing" Then when they've sent the message, it automatically comes through, and notifies you, right? Well my situation is, i send a message, it says that they've seen it. I'm waiting for a reply for about 10 minutes, i decide to refresh my page, as it turns out, they replied not long after i actually sent the message, do you understand what i'm saying? It's not automatically coming through.