External hard drive not recognized by 3.0 USB hub

Just received Plugable USB 3.0 7 port hub today through Amazon. 2 problems came up.

  1. After setting up hub to the computer, I tried attaching an external hard drive to the hub. It was able to recognize the external hard drive initially. But now when I attach it to the hub, the drive is no longer recognized even though I can hear the drive on. The drive is not even seen when I open Disk Management (under Administrative Tools).
  2. when I attach an external drive to hubs #5-7, the blue light doesn’t even come on but again I can hear the drive on.

Do I have a defective product???