First step when one has two or more My Cloud devices on the same local network is to make sure each My Cloud has it’s own unique name. If all My Cloud devices have the same name it could potentially cause routing issues.
Second, one may have to change the cloud access/remote access setting in the My Cloud Dashboard, on one or both My Cloud units, from auto to manual and setup port forwarding within their network router. Use different port numbers for each My Cloud. Its possible that if both My Cloud devices use the same automatic port values one might only get routed to one of their My Cloud’s rather than seeing either one. General how-to on setting up manual port forwarding:
And if one doesn’t know, when using MyCloud.com web portal one switches between multiple My Clouds using the gear icon.
Also note that everything in my post deals with the single bay/single drive My Cloud. Multi bay My Cloud units may operate differently or have different settings. The My Cloud Home is a completely different device with a different operating system and features and nothing indicated here applies to the My Cloud Home line of devices.