PTT button on Gamepad or Joystick doesn't work

When I try to use one button on my gamepad for PTT it will not register just that button. It will automatically add the mouse button or another button I press to get it to save. Why is PTT requiring the use of 2 buttons to work?

Gamepad is not officially supported by TeamSpeak. So their is no Guarantee that it would work. (TeamSpeak 5)

I was just wondering if there will be support for PTT on a HOTAS Joystick? I use this feature a lot on 3.6.