I unfortunately do not know much about the Xbox, let alone it’s streaming function, so I don’t think I would be of much help…
But maybe the Twitch guys know more of it, as they’re the one who made the program(s). Maybe look here for a possible solution.
If that doesn’t seem to resolve your issue, try the sending an email to twitch’s help-desk.
You can always try their live support on twitter. As well as reporting bugs, as this is definitely one of them.