www.makemkv.com

Hi,

I am a newbie, so sorry if this is on the wrong topic.

This is my first effort at backing up a Blu-ray disc. The issue I have is that the backup seems to complete without issue, but on playback the sound drops out after about 20 minutes in.

I am using a recently bought Verbatim Blu-Ray DVD-Drive 43888 usb-c drive attached to my MacBook Air, and I am playing the MKV file directly using VLC.

Does any one recognised the isseue, and how to resolve this?

It could just be VLC.
First try another free player, like MPC-BE. I have found that has cured a lot of jerky motion of compressed 265 videos, it might fix your audio issue as well. You could also try pot player but I prefer MPC-BE as the better option.

I did encounter an audio issue with videos ripped using davinci, and that turned out to be newer versions of VLC didn't handle the audio correctly. The fix was to revert to an older version of VLC which then played the audio perfectly - of course I had used MPC-BE to verify it wasn't a video file issue and of course turned out to be a player issue.

Hopefully for you it's just a player issue. Otherwise it could be an issue with your master disc. The odd time, a scratch on a bluray disc will cause a blip in the file - and VLC usually can't handle the blip properly and the audio either disappears or becomes out of sync. I vaguely recall that happening to me with a disc of mine, so much so I just gave up since bluray scratches are so difficult to deal with.