I’m in the process of resetting my Drobo. It runs latest firmware. I have 3 drives inserted in 1,2,3. I have a brand new replacement 2TB WD drive which I have tested in an external USB enclosure and it works perfectly. I plug it in to the bay 4 on the Drobo and … NOTHING. No light, no activity, the dashboard doesn’t show an extra 2TB drive at all.