www.makemkv.com

I can not find this issue but one similar post to which no one replied. It was about a specific movie but also had playback sync issues. Please forgive me if I missed it.
I have a bunch of movies copied to portable drives by two different machines (Windows). Viewing some of these movies I find a 2 to 10 second VIDEO lag (audio is usually ahead of video).

I am not referring to ripping errors. I have seen a FEW of those but not many.
I see this on most all videos regardless of machine used to playback or rip. DVDs and BR. Always using default settings, using older versions a few years ago but also on the most recent downloaded only a month ago.

It makes all movies seem like a cheap KungFu flick. But no discernable pattern. I am at a loss as to what I can try.

Sometimes the player is the culprit. Sometimes the computer isn't powerful enough. Sometimes IO bandwidth is limited. For instance, my computer is on the edge of being powerful enough to play 4K rips and sometimes it manifests as the audio being out of sync with the video.