This has been a bug for as long as I have been playing (since before the move to Steam). When using VOIP within the game, transmitting will sometimes get stuck and the person’s mic will be open until they press the button again. This is pretty easily replicated as I believe it’s connected to either hitting tab and talking or talking when dying. It might even be a random event.
I decided to report this even though there is a chance it’s been reported before as a person on the dev stream today mentioned it and the people on the stream didn’t even realize it’s an EXTREMELY common bug that happens every single game to multiple people. I constantly mash the button after I transmit just to make sure it eventually stops transmitting.