"What can you share with regards to the original system that was not synchronizing? " ← don’t quite understand your quiestion 
As i said operations systems are: 1 Mac (El Capitan) and 3 PC (Windows 7 and 8).
There is no local network, all computers are in one town but not in local network. They are connected through internet connection. I cannot get direct connect to WD My Cloud because he is standing behind NAT (internet provider) and router.
