Up arrow to bring last command won't work for commands executed while sleeping

When you are sleeping you can type anything in the chat (even commands). I noticed the other day on my server, that when you type anything, text, commands (successfuly or not), when you wake up you can't press the up arrow in the chat to bring them back. For Example if I typed "test" in the chat i could press T to open chat, up arrow and it retypes my last message (test). If I now try to type while sleeping "test2", for example, and send it, when I wake up I press T then up arrow and it brings back "test". No sign that "test2" was ever written. Strange....