Hi Phillip,
The word has to match at least one of the selected fields to search – at least partially. The other search does matches more results, because the word “noggin” is in the post contents – but those do not match the filter criteria though.
From the front-end I can also see that those results are from a different custom post type “plasmid”. Can you try selecting that custom post type as well on the General Options -> Sources panel: https://i.imgur.com/SFSNynf.png
