Cant access MyCloud from android mobile phone anymore

I dont know whats happened or even when it happened, but I can no longer access my WD MyCloud NAS Drive from my Android phone. It works fine when the phone is using the Wifi at home, but as soon as I am on network data, the MyCloud OS3 app cannot see the drive.

I used to be able to view Picture/Music and Video files that are stored on the drive, but for about three months now its not connecting

What do you mean by network data? What android phone do you own?

My Samsung Galaxy S20 5G works fine at home and when I am away using my providers, Verizon’s, connection. Sometimes I get 5G and others LTE.

In your Dashboard what is showing under Cloud Access for Cloud Devices?

Check the My Cloud Dashboard to see what firmware the My Cloud is running. If your My Cloud updated to the OS5, v5/x firmware, then one may need to update the My Cloud mobile app to the My Cloud OS5 app version.

If the My Cloud Dashboard is still on the OS3 firmware (v4.x or v2.x) the next thing to check is the connection statute for Remote Access/Cloud Access in the My Cloud Dashboard > Settings section. If the connection status doesn’t indicate a connection then one may have to disable Remote Access/Cloud Access, wait a few minutes then re-enable the option and wait for it to indicate a connection.