WD My Cloud - Device Offline in other Networks

Good morning,

recently i bought a WD My cloud device and set it up easily enough, and loaded files to drive.

Everything is working fine on my home network, but cannot connect using other wifi networks or via mobile 4G/3G. I get message "Device Offline’ 

I use a Linksys WAG200G modem and I have read that you must correct some ports.

Can anyone help?

Thanks in advance!

Are you using the WD App to connect?

Do you have Cloud Access turned on from the Dashboard?