There are actually two reasons for this.
Since the number of objects in the Pro version's database is large, the default setting for the catalog filter only shows a subset of objects. This often confuses new users of the Pro version, since they can't find objects that are visible in the Free version.
You can tweak the filters to suit your needs from the Catalog Filters screen.
The NGC and IC catalogs include a number of miscellaneous or ill-categorized objects, which are not enabled by default.
To enable them you can
pin them from the Catalog Filters screen.