When I move or rename some files on the left folder, during a sync with Echo action, the moved/renamed files will be treated as new files on the right folder, and those original files on the right folder are not deleted. I ended up with two copies of the
files on the right folder, one in the original location, one on the new location.
Example:
I have file X,Y,Z in folder A. Synced on both left and right folder.
Someday I move file X,Y into folder B. Now when I sync with Echo, on the right folder, folder B will be created as new, and file X,Y will be copied as new, while the original copy of X,Y,Z will remain in folder A.
Test:
If I create a new folder with some new file and test the sync, it will work perfectly as it should. It just doesn't work practically with actual file which I move and rename from time to time.