Yes this does seem to be the case as i find that my setup only truely works well when it is set up on static but without the UPnP which is odd. but i think this is to do with my router.
In terms of the wd2go: did you try setting up a new user account and accessing this?
Also when you get to the wd2go and log in what do you see? Does it just show a blank page?
When you log in first it shows devices: what do you see.
If you see device and click it askes for network drive password: what do you see
When you sign in what do you see?
As wd2go uses java could be an issue with the java - try reinstalling. Also it might think you have removed device which is why i was asking to try a new user account to access it to see if this resolves issue?
Also if you log in and in chrome clikc on the address bar lock what type of encyption is shown? mine says 256 bit - you might need to change yours in the network and sharing center under file sharing connections to 128 bit.
Also in network and sharing enable all sharing buttons and see if this changes anything.
let me know how you get on…