WooCommerce Product Bundles
If you have the WooCommerce Product Bundles plugin installed and your facets are not filtering properly, make sure to enable “Advanced query detection” in FacetWP’s settings. (This setting was called “Strict query detection” in FacetWP versions older than v4.5).
This issue will only happen if there are product bundles in the cart. In that situation, this plugin creates a product query for the bundle that runs before the main WooCommerce query on the page. This product query wrongly gets auto-detected by FacetWP as the query to use for filtering, instead of the actual main query. When “Strict query detection” is used, the product bundle query will be ignored.