One option I would suggest if it is available on your Router settings i.e. enabling UPNP which will provide direct access to the My Book Live and communication speed will be faster than relay. By the way what is the Router being used. I would suggest contacting WD technical support through phone call so we can investiagte the issue right away
Enabling UPNP needs to done on your Router configuration. I would still suggest you calling WD support and we can arrange appropriate engineer right away to look into the problem