Just a thought, but try a pathping to the server. I don't know the ip address for your server but just open a cmd prompt and type in pathping ipaddress. It will give you the latency for each hop of the trip to the server and if there is any loss at any of the hops. If you have a good latency and no loss in any of the hops it's something with the client server and maybe customer support can help you at that point.