There are 2 audio options for most bluetooth.
Bluetooth Audio Renderer, which is for high quality sound output.
Bluetooth Hands-Free Audio, which is telephone 8k audio quality. Apparently, this works with VA, but not the High quality sound option.
The problem with Hands-Free though is, it lags big time, so what it does to try to fix that is load up a buffer. Let's say you're listening to a book, or watching a tv show, and you pause it, well, the headset will just keep playing, because it's running off a buffer, and it will keep playing for a few minutes too. It's just not a mode you want to use. Audio Renderer mode is the best. You pause it, or skip forward or back, and the audio keeps up.
But if I use that mode in VA, I can't hear anything.