Airplay sound not working with Samsung TV

I have connected my Macbook to our Samsung TV (Class **7000

Crystal UHD) with Airplay and while the screen shows fine the sound doesn't work. The sound does work when I connect to the TV with my iPhone however. I have also contacted Samsung support and they said it must be something to do with the Macbook settings since the sound works with the iPhone. I have checked on settings and the TV appears as the output.