The expected behavior in IS facets API is to not bring facets with hidden true, but, there are some exceptions for that, for example when the facet is selected in the query, the API brings the facet in the results with the hidden prop as true, and we are not considering this information

Filter for a query with the hidden facet, like for example:

https://storeframework.vtex.app/new-collection?productclusternames=new-collection&fuzzy=0&operator=and&facets=productclusternames%2Cfuzzy%2Coperator&sort=score_desc&page=0

In this case, productClusterNames is set as hidden but, since it's being filtered, it displays in the filter navigator

N/A