For hybrid queries, pass filterOverride in the vector query when the filter must constrain vector results too; the top-level filter only covers the text side. If results look unfiltered on the vector half, this is the first thing to check. Also set k to at least 50 when using the semantic ranker, since it returns fewer results from too-small input sets.

Context: Official docs mirror (hybrid search how-to): documents the gotcha that a global filter is not applied to vector queries in Azure AI Search. If you need filtering on the vector portion of a hybrid query, you must use filterOverride inside the vector query itself (preview). Agents that set only the top-level filter will see unfiltered vector results mixed in.