Thank you for the patience, It seems that the issue was the filter. It seems you added the Post Parent filter and not the Post Relationship filter since you are listing what are essentially brother/sister posts correct?
I changed my theme to Newspaper and Content temples was not working. I registered the function get_content and I can able to see content templates are working but the Sibling/Brother pages are showing as No items found.
When I change theme it is working fine but the same views is giving no result for Newspaper themes.