Cannot connect to MyCloud after setting up WiFi Extender on network

** UPDATE **

OK something strange. I am setting up my sisters laptop for her and have just finished reinstalling the OS and everything from scratch, its a Macbook.

 

After loading the OS i just found the MyCloud drive available in the Finder, and i am able to connect to the drive through the laptop and access the Public folder.

However, trying to connect on my own iMac which is the main computer i setup the MyCloud drive on i cannot connect!

I also just tried on my mums Windows laptop and again was able to connect to the public folder with no problems.

 

Does this narrow down the problem to something else more specific?