I just got build 280 from support to help with a similar sync issue on galaxy note 8. the device would sync everything, then delete it all and sync again, over and over. battery would drain to zero in less than 12 hours.
Sync seems fine now, no repeats. however it did inexplicably stop syncing after about 18 hours, wouldn't sync again until device was rebooted. Will see whether this recurs or if it was a one-off glitch.

The kb article listed different symptoms on a galaxy S8, and mentioned the device switching between AS 14.1 and 16. I'm not sure the switching was happening before, but now it shows AS 14.1 in the mobility console. That might be what the fix does - set Galaxy 8-series devices to AS 14.1.