No audio when using MPV on one Apple TV

[Skopin 10]

Hi everyone, having a very strange issue with Emby on one of my Apple TVs. Everything was working up until a few days ago. Now, any video I play has no audio.

After a bunch of troubleshooting, I was able to get audio to work only if I changed the playback settings to use the ATV native player. Setting it to auto or MPV gives no audio.

This is happening regardless of the codecs; every video has the same issue. It is also only happening on one Apple TV. I have three, and everything works fine on the other two. 

I have tried restarting the server, restarting the Apple TV itself, and uninstalling and reinstalling the Emby app. I've also tried to force transcoding (the videos usually direct play) and the issue persists. Any help on this would be greatly appreciated.