What search are you doing, and what items are appearing that do not match your search terms?
If a search returns no results, eBay will often drop a search term and provide results that match fewer words. If you are scrolling quickly you may not see the note indicating that has happened.
Sponsored listings may not necessarily match all your search terms, either.
Sometimes eBay's search will group certain keywords, and treat the grouped words as a unique keyword, complicating search.
If you are using Best Match, that might change your search results, either by adding additional results that are linked via product item-specifics (and those may not even appear in the listing itself) or by excluding certain results that may appear in other sorts.
