Answer
This is very likely a display-filter difference, not a missing grant — by default, that tree view can be filtered to show only 'Not Granted' objects, so an object that's already granted in Production (unlike in Test, where it might genuinely be ungranted) simply won't appear in that filtered view. Right-click the root of the Presentation Objects tree and toggle between 'Show Granted' and 'Show Not Granted' to confirm whether the object is actually already granted (and just hidden by the current filter) before assuming it needs to be re-added.