I do a search with a partial text string and get results:
I then hit the “show all results” button and am told that no results were found:
That is as expected.
The “search as you type” suggestions in the dropdown use a search on partial words (it has to, because otherwise suggestions wouldn’t work).
But the ACTUAL search uses a whole words search only.
So “sat” won’t give you any results, but “saturday” will.