Can't connect to WD MyCloud Drive away from home

My Cloud OS 3 Personal & Network Attached Storage My Cloud
2

See if this gets you anywhere:

http://community.wd.com/t5/WD-My-Cloud/HOW-TO-Troubleshooting-Remote-Connectivity-Issues/m-p/617261#M1130

See specifically the connection test sections and see if you can try them when you’re on a remote WiFi network.