Server Version#: 1.24.0.4930
Player Version#: 7.22 (on tvOS 14.7, Apple TV 4K)
Since updating the AppleTV app to v7.22 I can no longer hear the audio in MKV files where the audio is transcoded TrueHD->FLAC or direct play AC3 5.1. All I hear is some low frequency rumble with no intelligent audio.
This worked fine on the previous version installed. The only change I made to the system was to update the player app for the new UI.
Updated tvOS to the public beta version of tvOS 15 and audio now plays again.
Looks like whatever was tweaked to fix the issue on tvOS 15 broke it on tvOS 14…