I can’t tell for sure only from the screenshot, it looks like those results are likely matching the other keywords (or partial matches for the other words), even if they are not highlighted. Searching “is” and “what” can still match partially other words, which may contain these strings, like “whatnot” or “louis” for example.
Try enforcing a more strict keyword logic, that should make sure that only complete keyword matches are allowed: https://i.imgur.com/hmWob1d.png
That will make sure to only allow full keyword matches, and only if the phrase is matching all of the keywords in any order.
