Dashboard can no longer see Drobo 5n2


Dear all,

NB first time post

I have been running my drobo 5n2 for over a year now with very few issues indeed. It sits in the corner of the room running with 5 disks and I have been happily controlling it from the dashboard when needed. It holds work, and personal data and a lot of it valuable for my daily use.
However, since March 2019, the dashboard will no longer see the drobo.
I have I feel tried absolutely everything to fix this on this:

When issue started:
Running Mac OS El Capitan

Updated Drobo Firmware to latest 4.41 (I think) in March.
Updated to 3.42 dashboard in March

Since then to troubleshoot:
Reset the Buffalo WSR router
Updated OS on Mac to High Sierra (cant use Mojave)
Reinstalled Dashboard multiple times and even downgraded.
Taken out Drobo drives and reseated them,

I can ping the drobo from my mac but dashboard will not see it so I believe that the recent firmware has rendered it useless for the time being. Its the only thing that has changed or I ever do on the drobo.
I have also read that there was a change in Security with High Sierra on the OS and I have gone through the process to troubleshoot this as well to no avail. In system preferences/security and privacy there should be a prompt to allow me to see the DD Service and allow access but after multiple installs I have not seen this either, so Apple could also have a say in this too.

If there is someone that can help on here who has experienced this recently please let me know how you fixed it. I would really very much appreciate any advice, as mentioned I feel I have tried everything but suspect this is a communication protocol/network issue between the drobo and the mac dashboard.
Many thanks in advance