I will try to explain, but it will be a bit messy.
Few days ago we enabled voice chat feature on our servers. We have more than one server. Everything was fine for me untill last days - people can't hear me anymore. I see my nickname at the right side of screen when I press voice chating button, but for others my nick gets stuck there and they cant hear me. If I reconnect, they can hear me, but untill they reconnect or some new players come, they wont hear me again. On few servers it is ok all the time, but on others I have this bug. I am not the only one with such problem. Was talking with my friend online and next day we both are bugged.
Not sure about this one, but when I change my nickname it is working fine again. Changed back - bugged. That's weird..
Also I can hear others who aren't bugged.