Custom Single Listing Page not working

The Custom Single Listing Page isn’t working. I created a custom page in Elementor, add the shortcodes etc. as per documentation.
Page slug is listing-template.
Enabled in Directory Builder > Single Page Layout > Other Settings > Custom Single Listing Page (set page and enabled).

However the single listing isn’t redirecting and staying in the generic Directorist listing template. No caching and permalinks re-saved.

Could this be a child theme issue? We are using the One Listing theme with the One Listing Child Theme (as provided by wpwax).

Thank you kindly.