Thanks for the answer. The images attached should show all of the relevant parts.
The data source within the original sub page.
The basic repeater on the original sub-page.
The design tab on the homepage showing the 'broken icon' where the gallery should appear and the tree for the site.
The Hierarchical Viewer top part.
The Hierarchical Viewer bottom part.
The path is blank to allow to allow the inclusion of all sub-pages. The page type filter then selects which are allowed and does have the Gallery page listed. The transformation used for the pages are the same.
Hopefully these screenshots include all of the settings that should make a difference.