Cannot See Relevance Search as part of Preview Features

Hello,

We have been testing the Relevance Search preview feature in our sandbox environment for a couple of months now and had no problem enabling it under Settings > Administration > Previews. 

However, we recently took the CRM 2016 Update 1 update for our production environment and I cannot see the preview feature for Relevance Search 

under Settings > Administration > Previews. 

Both environments are Microsoft Dynamics CRM Online 2016 Update(8.1.0.534) but our sandbox environment has (DB 8.1.0.526) listed while the production environment has a newer version - (DB 8.1.0.534) - is this why we cannot enable the Relevance Search preview?

Any information would be appreciated.

Thanks!

Bryan