So basically it’s a WordPress hook (not ACF hook), reference:
Top level pages admin.php?page={page_slug} toplevel_page_{page_slug}
Sub pages admin.php?page={page_slug} {parent_slug}_page_{page_slug}
https://codex.wordpress.org/Plugin_API/Admin_Screen_Reference
Thank you @hube2 for this ! 🙂
@roby94 reference says it is using slugs, and your final code does not corresponde with your initial code, so I just don’t believe it started using titles, that would be horrible approach.
