I'm in the process of implementing ArcGIS Data Store, and a part of that process involves first designating a hosting server. I have just upgraded everything on our Sandbox to version 10.6.1 (ArcGIS Enterprise and ArcGIS Desktop). I am going through the steps on our isolated sandbox server first in case I blow something up. When I get to the window in Portal for ArcGIS (Organization ► Edit Settings ► Servers), the drop-down under "Hosting Server" is empty. However, when I review the same drop-down under Hosting Server in our production environment, an option is available:


The Sandbox is supposed to be an exact copy of what is in Production...so how could there be a discrepancy? How do I ensure that there is indeed a Hosting Server option here? From where is Portal retrieving this Hosting Server path?
Thanks