This is actually a quirk of Instantsearch.js, which is the OSS UI library that we used to build that UI. When you apply a filter and also facet, if you look at the network requests to Typesense in the browser's dev console, Instantsearch sends two requests inside one multi_search request. And then in the facet counts, instead of using the facet count from the query with the filter, it uses the facet count from the other query which is supposed to give you the counts for the unfiltered items.