I have a brand new 1TB Xbox One connected straight to the TV via HDMI (audio + video), just installed the Blu-Ray app last night, played a new DVD for the first time and within a few minutes the audio was clearly out of sync by 250-500 ms. It didn't get worse than that, but it was distracting and noticeable (and pausing/unpausing didn't really change that).
I see the audio sync problem has a long history here, and I've read of people uninstalling/reinstalling the app and so on, but the xbox is brand new and the app is freshly installed so it should all be current (and my audio settings are at their defaults right now too). I highly doubt it's the hardware so I wonder, has this app problem ever been resolved successfully for such a straightforward configuration as I have? No amp, no optical, just HDMI straight to a normal TV (one that never has this problem with other sources, including the Xbox 360).