I've confirmed it works fine with mine when I switched to NAS-to-NAS sync with my NAS(es). However, I was originally using the RTRR function between multiple QNAP NAS, and the problem persisted there.oyvindo wrote:Let me add that RTRR sync between two folders on the same NAS, as well as NAS-2-NAS backup works ok. This problem is ONLY related to backup to an external USB device, as far as I can see....
I also do periodic RTRR syncs from my TVS-871 NAS to a DAS device attached to a Windows 10 PC [using "Windows Share CIFS/SMB)"], and it doesn't do the unnecessary updating (or re-copying) through that mechanism.