In SharePoint 2013 / SharePoint online you may come across a weird thing where:
– You create a result source & verify the results & all appear correct
– Configure a search results webpart to use your new result source but you see numerous results missing
This is typically happening because by default the search results webpart is automatically trimming what it classes as duplicate results.
Export your OOTB search results webpart & edit the XML:
– Look for TrimDuplicates”:true
– Replace it with TrimDuplicates”:false
Now save your new search results webpart, add it to a page & compare your search results, you weren’t going mad after all 🙂