Drobo 5n2 - drobo access - err_cert_revoked

I’m having issues having users connect to my user.mydrobo.com Drobo Access through their browser. It returns a ‘Your Connection Is Not Private’ message and says ‘NET::ERR_CERT_REVOKED’ which from what I’ve read is that there is no updated SSL certificate in place.

Has anyone else experienced this issue? How would I go about resolving this issue?