Sync Manager creates new copies of files on USB instead of.... syncing

Every time I use Sync Manager to update my USB drive, instead of “synchronizing” (checking to see what’s missing and copying over the changes), it creates new copies of every music file on the drive.

So I have performed the sync operation 3 times now, now each track has 3 copies of itself on the usb drive taking up way more space than required. It also obviously takes forever to copy over 1000+ tracks, the vast majority of which are already on the drive. This seems like obviously unintended behavior… Is this a bug or am I doing something wrong?

It looks to be by design, though it shouldn’t work this way, it should just update and add what is missing. Shouldn’t be re-adding the music files that are already there.

It does not behave that way with me. It should only update with new tracks, and update previous tracks with new metadata