Call that a false alarm. I think the issue is in the input file.
I while I do not know the exact parameters of the issue, it is now easy to imagine.
For the record:
I used VLC to rip the DVDs and - for the one in question - it produced a 4GB 6 hour .mp4 file. 6 hour and 4GB are consistent for resolution a 1990s camcorder was capable of. I replayed the DVD and there is only 2 hours of video!!! Looking at the .mp4 file, those 2hrs appear 3 times (one after the other). So I am assuming there are many oddball pieces of data in the .mp4 file ... this could explain the issue Debut had ... along with issues encountered by Handbrake, android phone, iphone, MakeMKV, MP4Tools, ffmpeg, Media Player, Windows Media Player, smart TV, PS4, and ClipChamp.
Thanks for the response
Jonathan