B810n won't connect to dashboard after power failure

Hi, I have a 2 x B810n’s. One configured as the primary and one as the backup, synced using DR.

The Primary device has failed to reconnect to the dashboard after a power failure. I have tried restarting the Drobo a number of times, but is just won’t connect. The lights all look fine and I can ping the device IP address, but I am unable to map a drive to it.

I am running a windows 2012 server with the dashboard installed and the backup unit is being seen fine.

Any suggestions on thing to try to get it up and working again would be appreciated.