When searching without a term on Italy, the left sidebar show 23 results for pages. However when filtering on pages no results are returned.
Search without filters showing 23 pages in sideabar: https://www.greenpeace.org/italy/?s=&orderby=_score
Only came across this for Italy, but didn't check all sites so there could be more. Happens there on dev, staging and prod.
It could be related to Take Action pages: these are also pages but there is some logic in the search to treat both separately. So the filter on pages will exclude Take Action pages, and the number in the sidebar for pages is total number of pages - number of Take Action pages.