My Cloud with intermitent access through internet

Every day, My Cloud loses connection through via app in my mobile but if I am inside the WIFI where the My Cloud is installed I can access normally. If I go to the My Cloud setup, it starts working normally but in day after the problem come back. Does anybody know what is going on?

Is this happening on a particular WiFi network outside your local network, or does this happen while on your data plan as well? Does rebooting your phone correct this behavior?

Im my particular WIFI works perfectly. The issue happens when I am using the 3G or 4G in my mobile.
Thank you.