I’ve been buying physical media and want to save digital copies for SD card. I had no issues with my CD for music but DVDs don’t work.
I have an optical drive that I plug in and it works. VLC with libdvdcss installed through Discovery failed. I tried MakeMKV but it doesn’t detect the optical drive.
If you got MakeMKV via Flatpak, you may want to get Flatseal, and manage permissions. It may not have access to that device.
This is the first I’ve heard of flatseal I’ll definitely check it out and see
Flatpaks are often restricted on what resources they can access because of how they work. I am not sure of the exact option you will need; but my guess is under devices, you can allow USB devices, and specific folder paths and it may work.
There’s also “application permissions” in settings
I use makeMKV as a Flatpak and never had to change any of the permissions, although it’s true that F’atpaks have restrictions.
But I never tried it on my Steam Deck.
Maybe OP has another computer he could try MakeMKV on.
My thought is because of USB access. It wouldn’t allow that by default. But if OP has a computer with a built in drive, it’s worth a test.