Agnes on "[Plugin: Next Page, Not Next Post] Loop does not behave"

I am using the shortcodes in pages with parents and child
[next_page] and [ previous_page]

It keeps showing, on every page, the same previous page and nothing as next page.
I have tried to change the order of pages in post editor (with 201, 202, 2013 etc, it does not help.
I have tried various variations of loop and get_pages, with of without "" (not sure if they should be there)

[next_page loop=expand] and [previous_page loop=expand]
[next_page loop=cousinsloop] and [previous_page loop=cousinsloop]
[next_page loop=cousins] and [previous_page loop=cousins]

[next_page loop="expand"] and [previous_page loop="expand"]

[previous_page get_pages_query="sort_column=post_title&sort_order=asc"] and
[next_page get_pages_query="sort_column=post_title&sort_order=asc"]
[previous_page get_pages_query="sort_column=menu_order&sort_order=asc"] and
[next_page get_pages_query="sort_column=menu_order&sort_order=asc"]

Nothing seems to work...?

https://wordpress.org/plugins/next-page-not-next-post/