www.makemkv.com

Just another opinion: I had ripped around 70 DVDs with RipGuard (and around 9 with ARccOS) and not a single one couldn't be worked with my ASUS BW-16D1HT. "Of course" you see a difference in the parts where RipGuard belongs to. Looking at your Hexcode from ddrescue you must notice, that th...

You might try a different DVD Opening Mode to see, if the results differ.

Could be a copy protection like RipGuard

If you make a backup of a DVD, you can extract the ISO file as the CSS has been removed during backup.

Is that drive connected internally or in an external enclosure?

If internally, can you try to use a different SATA cable? Or at least check, if the cables are connected correctly?

If external, what kind of enclosure is it?

Try using a different DVD opening mode

maybe take out the CD-ROM which seem to be in the drive and keep the drive empty while looking up the info on MakeMKV

The Matroska format itself is not deterministic by default when it comes for header and metadata.

But the streams should already be always the same if there wasn't any error on dumping.

You also could use something like Icaros to let Windows display a random frame as thumbnail. Still better than nothing.

you might have a thumbnail provider for video files, they usually just take one random frame from the video. The image file in the cover would always be the same.

It is usually a cover image, which is e.g. shown in Windows File Explorer when thumbnails are shown for video files.

Little detail: CSS protection will be removed upon backup.

I can confirm, that MakeMKV has no problems with RipGuard or ARccOS. I myself had many DVDs (on BluRays there is no such copy protection) with that and MakeMKV read them without problems. As much as I know, e.g. RipGuard has a certain string in the first sectors of the discs sectors, thus MakeMKV kn...

For preservation you can use DiscImageCreator or Redumper like the ReDump project does: http://wiki.redump.org/index.php?title=Dumping_Guides

I don't think, it is upon MakeMKVs target to do such a thing.

Does it happen with the/a previous version?

https://makemkv.com/download/old/

and makemkv proposes to rip all 5 of them, however if i "enlarge" one title by clicking upon it, it proposes (so it seems) to rip only the Audio section, and Video is not checkmarked; This is not correct. The video part is always ripped. you just cannot see or remove the checkmark for it....