What does the Site Subscription Criteria look like?
When you select the OSD site in the left-hand pane of the “All Content” domain, by default it looks like this:
The part I highlight shows that I have not specified any custom criteria for the site, and all clients that meet the BigFix -provided “External Subscription Constraints” will subscribe to the site.
Compare with this Beta site, for which I have specified an additional (local) subscription criteria -
You may find that in your deployment there is a custom subscription criteria defined and you would need to modify that criteria (which requires logging in as a Master Operator)