I wanted to post a thread here even though it's a duplicate of this issue:
https://community.getchannels.com/t/live-tv-playing-in-slow-motion-on-apple-tv-4k
https://community.getchannels.com/t/live-tv-audio-desync-after-an-hour-on-apple-tv/
Because those threads seem to be very focused on it being an Apple TV problem specifically. It's not. It's also happening on the android TV app with any 1080i live TV show or recording that lasts longer than 1 hour.
The playback gets slow and audio goes out of sync. If you seek forward or backward in a recording when this happens, it can solve it, but it tends to jump to a very different part of the recording, usually several minutes later.