The VideoLAN Forums

I have a MP4 videos made in 2014. They reside in my main drive G. They are also backed up on drives H and I.
I typically do not use originals (experience from past when using something and system crashes and corrupts data), so I use the backups from drive I.
I found last night that the folder (on drive I) that has these twelve videos, two of them are out of synch. I play these weekly and they been fine until last night.
I was able to play them in Windows Media Player and they played fine.
I rebooted system but the same videos will stay out of synch in VLC.
I tested the original videos in G and the other backups in H and they are also out of synch. So my originals are affected. The creation/modify date of all the videos are still 2014.
I do not understand why all of the sudden this is happening even to my originals, and to only two or three videos in a folder for a dozen.
In VLC, I can play with the audio delay to get close enough to match, but to do this every time I play this playlist is troublesome. Also am concerned why my originals are doing the same but the dates not changed.
Any thoughts?
Thank you.

There is another similar report here:
https://forum.videolan.org/viewtopic.php?f=2&t=161360

Please upload a log and a sample file as explained in the above thread.

Thanks.
I read that post and it sounds similar to an ongoing issue I posted above MOV files.
I will post this question over there then too, as I not understand why this group of MP4 files I use weekly all of the sudden are out of synch.