MyCloud and MyBook

I have a 3TB MyCloud. I got a good price on a 3TB MyBook and thought that I could just plug that into the MyCloud and be able to back up the MyCloud to the MyBook. Everytime I plug the MyBook into the MyCloud, it hoses the internet connection and I can’t access the MyCloud.

At first I could see “MyBook” as a folder but couldn’t see it’s contents. Now, everytime I plug it into the MyBook I can’t even see the MyCloud.

Anyone know what is going on? I am ready to return the MyBook.

I’d test if this happens as well with other external drives. If it’s only related to the My Book then formatting the drive again to clean it or changing the USB cable might help.