In game mic not working

Using wireless Razer Thresher on Xbox one. In game mic not working, sound coming thru okay but can't chat. Mic appears to be working in party chat setup on main xbox screen but not when load into game play e.g. call of duty or fortnite squads. Have tried switching between party chat and game chat. Have tried turning on and off party in main xbox screen. Have tried updating controllers (but headset is wireless and not plugged into them anyway). Any ideas much appreciated.