Hi!
Thank you for the details, it helps a lot!
I am not entirely sure, but there seems to be an empty space after the name in the following post: https://australia-ain.eblue-hosting.co.uk/wp-admin/post.php?post=803&action=edit
Looks like that is applied to the filter, and only this item is returned. Can you try removing the space character after the “Violet Bentley” name (and then reloading the search on the front-end), to see if that helps?