Looking for my previous post about Android auto having no sound in beta, for those that are seeing the same issue it should be noted I am seeing mine when I plug my phone into my auto mobile interface. Android auto seems to work fine when it's running on the phone only. Plugging it into the vehicle produces no sound output or a chopped up audio feedback that is not audible.
I have another issue in addition to no sound from Google Assistant on Android Auto. This is a pain.
If I take a picture and then share with WhatsApp the picture will not be sent to WhatsApp. This error also occurs when sending the picture from Google Photos or Samsung Gallary or from the the camera app as mentioned. At the moment I simply use the paper clip within Whats App.
Sending pictures to Telegram or Samsung messages works fine for me.
Samsung has reported the issue to WhatsApp. Fix on the way.
It's only no sound from Google Assistant on Android Auto that is a pain.