www.makemkv.com

I keep getting "Backup Failed" with about 1:12:00 remaining in backup

MakeMKV v1.15.1 darwin(x64-release) started
Debug logging enabled, log will be saved as /Users/petermoorhead/MakeMKV_log.txt
Optical drive "DVD+R-DL HL-DT-ST DVDRW GX40N RQ00d" opened in OS access mode.
Optical drive "BD-RE MATSHITA BD-MLT UJ260AF 1.00d" opened in OS access mode.
Backing up disc into folder "/Users/~/Movies/backup/SHINE_A_LIGHT"
Downloading latest SDF to /Users/~/Movies/backup ...
Loaded content hash table, will verify integrity of M2TS files.
Error 'Scsi error - MEDIUM ERROR:NO SEEK COMPLETE' occurred while reading '/BDMV/STREAM/00001.m2ts' at offset '20415971328'
DEBUG: Code 0 at V3gPp\M6EEg{/Wa_19-:121266189
DEBUG: Code 0 at V3gPp\M6EEg{/Wa_19-:213133365
DEBUG: Code 0 at rq^4S>xw?lhk(r?iT\nb:29396920
Encountered 6 errors of type 'Read Error' - see http://www.makemkv.com/errors/read/
Backup failed

On multiple attempts, does it always fail at the same offset, or "in the area"?

When doing a backup, the drive usually isn't sent off to random places, so seeks should go to legal parts of the disk. Breaking at the same offset each time could point to a defect in the disk. Things like this can happen if the drive tries to switch layers, and cannot refocus the laser properly.

If it's "in the area" (not the same spot each time), it can be a smudge.