Problems streaming movie from Mac to Apple TV

Hi everyone,

I'm attempting to use AirPlay to stream a movie from my MacBook Air to an Apple TV using the TV app on the Mac, and I am encountering a few issues. I have the movie all set up on my Mac with audio description enabled and with no subtitles, but as soon as I change the location to the Apple TV, the movie comes through on the TV, but there is no audio description, and subtitles appear on the screen in a different language. I have never encountered these problems before, streaming from an iPhone or iPad to that Apple TV, but this was the first time I tried with my Mac. Has anyone encountered this issue before? If so, is there a way of remedying it? I'm new to the Mac, so I could be missing something totally obvious.
My Mac and the Apple TV are running their respective latest operating systems.

Thanks for any help,

Melissa