So lets give one of my old post a try.
http://community.wd.com/t5/WD-My-Cloud/Call-me-maybe-WD-Connectivity-Issues/m-p/881610#M35919
Let me know either here or on that post whether it works.
If not, my other guess would be to do a full reset. I’ve read in this forum that sometimes after a firmware update the Cloud requires a full reset to work.