Drobo 5D keeps unmounting

I recently added a larger drive to my Drobo 5N. One of my 6T was failing so I replaced it with a 10T.
When starting up I get one red light and four green. Then all the lights flash yellow and then it unmounts and starts all over again. I do see my Drobo on the desktop while lights are flashing.

It is maddening. No help from support and I am thinking about buying a new machine and migrating the drives. Any advice would be greatly appreciated.