TFT connectivity and Nav VI

Hi.

Can anyone help me. I have just upgraded to a 2018 GS with TFT screen.

I have connected my BMW comms system helmet and iPhone to the TFT screen which works fine but can’t get any audio feedback from my Navigator VI.

If I then connect my helmet back to the NAv VI I lose the connectivity to the TFT screen.

Any ideas how I can connect so I can get feedback from the Nav VI via the TFT connection.

Thanks

There is a very similar thread on the second page if you look for it

Many thanks. Found the thread.