Its a known issue some of us have experienced when using an unbrick procedure on a new hard drive that gets installed to the My Cloud enclosure. Here is my specific post in a thread I started on this issue that explains how I fixed it (for the two drives I used) and was able to successfully upgrade to the latest v4.x firmware. It involved repairing the GTP on the hard drive at the start of the “unbrick” process.
https://community.wd.com/t/unbrick-then-firmware-upgrade-equals-no-dashboard/136666/6
