After upgrade, rclone sync wants to do a full copy not just of deltas

[nielash (Niel)]

Possible explanation:

OneDrive modified time tolerance change?

The precision did increase by 3 decimal points (on OneDrive Personal only), as part of the project to add metadata support. It is documented here: mtime Time of last modification with S accuracy (mS for OneDrive Personal). but I agree that in hindsight it probably should have been mentioned separately in the changelog! --modify-window 1s should restore the old behavior, if you prefer.