I gave up on Cortana for any voice function.
Even when it isn't giving me unsolicited web searches, it's too slow for basic multimedia functions like "pause." The standard "Xbox [blank]" commands feel almost magically fast in retrospect. They need to strip this rubbish out of the OS.
There once was a week in preview when "Cortana, pause/play" worked nearly immediately, but its useless right now.
So my Xbox is downloading a 250mb update. Haven't turned it on in about a week. I'm assuming this is the new update?
New update is 4 GB.