"My Cloud" visible in browser but not as mapped drive

My Cloud OS 3 Personal & Network Attached Storage My Cloud
6

What brand/model router did you change to? If an AT&T Uverse router or one of the routers listed in the following WD Support document there is a know issue with those routers and the My Cloud. The solution/workaround is to put a switch between the My Cloud and router.

https://support.wdc.com/knowledgebase/answer.aspx?ID=15086