Sorry, I figured I would save my breath, in case it wasn't needed;
Simplistically, a sleep between the commands in that simple while command will allow them all to succeed.
see below..
So, this initially indicates to me that perhaps some sort of chat buffer was added, maybe to reduce spam.
This was corrected, when you said nothing notable had been adjusted.
What makes me believe that this is a problem, is that the commands/messages are not simply held for a determined amount of time, and then sent in chunks, following this "buffer" restriction. They will simply come rolling in all at once.
So.. To re-iterate, on a simplistic while command, only the first two commands will make it through. (Mentioned chat buffer?)However, once something interacts with the chat, those delayed messages all come rolling through, irregardless of that prior insinuated 2-message maximum.
The number of messages that get pushed through, before waiting, can infrequently vary, although typically it is all of them -- again, making this issue seen very non-logical.
Since the update, I have been able to reproduce this response across many game servers and scripting methods/environments. While this cannot be reproduced under general usage, sending more than two commands in rapid succession seem to suffer from this oddity.