Just updated to macOS 10.15.2 per Apple update today. Drobo5C connected - DD shows all good. When Mac returned from it’s rebooting, DD did not show Drobo5C and Drobo5C icon on desktop was generic. Tried double clicking into drive but got a -50 error. Moments later on its own I got a ‘disk not ejected properly’ error.
Drobo are not handling the macOS properly - you are not handling reboots at a minimum. Right now I have to reboot the Drobo5C by hand. This should not be this way.
DD = 3.4.2
5C FW = 4.1.4