Jul 30 15:31:28 mini kernel: sr 2:0:0:0: [sr0] tag#0 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE cmd_age=8s
Jul 30 15:31:28 mini kernel: sr 2:0:0:0: [sr0] tag#0 Sense Key : Hardware Error [current]
Jul 30 15:31:28 mini kernel: sr 2:0:0:0: [sr0] tag#0 Add. Sense: Timeout on logical unit
Jul 30 15:31:28 mini kernel: sr 2:0:0:0: [sr0] tag#0 CDB: Read(10) 28 00 00 00 7f 40 00 00 c0 00
Jul 30 15:31:28 mini kernel: blk_update_request: critical target error, dev sr0, sector 130304 op 0x0:(READ) flags 0x0 phys_seg 26 prio class 0
Well that sucks. Look at the physical disc; no scratches, no fingerprints. Cleaned it, tried again, failed. Try doing a backup instead of an mkv rip (I've had some success with this in the past): that works! Great, now I have a decrypted copy I can work with locally without having the drive or USB bus get in the way.
Try to play the decrypted version with vlc: aaaaaaand, it hates it, because regions. Bleh. Try playing the individual m2ts files with mpv, and everything looks great, no issues. That's promising.
So, try building an mkv from the backup: fails, same error. Huh. That's weird. Downgrade to 1.15.1, same probem. Downgrade to 1.15.0, and...... it works. So, my personal problem is solved, but it seems there's something going on here.

MakeMKV logs from 1.15.1 attached. Happy to run additional tests if it'd be helpful.