I have what seems to be a linked issue.
In a menu, I use:
wp_list_pages( 'title_li=&include=16,18,20' );
This menu should list those 3 pages and their children, which is what it used to do, but not anymore.
Now I need to include the ids of all the children if I want them to show.
After testing, the same goes for:
wp_list_categories( 'title_li=&include=5' );
Used to show the category and its children in the menu, not anymore, unless I include the ids of the children…