CHAT CLIENT BUG: In client whispers not being delivered between players

So here's the scenario I witnessed multiple times:

1. I'm not in game, just typing to a friend using the chat client.
2. My friend is in game, they're replying to me using /r.
3. I'm watching them on stream, so i can see them typing a message to me.
4. Their message never appears in my message box on the client.
5. Sometimes the message goes through, sometimes it doesn't.

Please figure this one out rito, just imagine how much worse the community could become if your servers were routinely performing man-in-the-middle attacks on your sensitive players!