I backup four 3 TB drives regularly that have a music collection.
I use an external hard drive USB 3 dock to hold the appropriate target hard drive.
Three of the four source drives backup without a problem, initially with a full-backup and then incremental backups.
However, the fourth drive does not backup correctly. A full backup will proceed without problems but incremental backups always result in another full backup.
BackUp Maker is set up the same way for each drive so there must be some characteristic of the source drive or the target drive of the fourth drive that is causing the problem.
Thanks for any help.