This only happens to me on HALO MCC whether its GAME CHAT or a PARTY CHAT FYI.
I have figured this one out. At least I think I have.
DO you use an MS STEREO HEADSET Adapter to use the MS Headset or another headset like a Turtlebeach X12.
Whenever I use it about every other match after it backs to the lobby I have to UNPLUG the HEADSET ADAPTER PUCK to get chat back.
IF I use the el cheapo voice chat headset that came with the Xbox ONE that NEVER Happens.
So there it is.
HOPE they PATCH that for next time…