I have two collections,

products

and

inventory

. The inventory collection is joined to the products collection with a reference, like so:

{
  "index": true,
  "name": "product_id",
  "reference": "products.id",
  "type": "string"
}

I want to return the inventory fields when I do a search on the products table. If I perform a search on the products collection and I set the filter parameter to

filter_by:$inventory(*)

, the inventory fields are returned in the query results. However, if i set the include parameter to

include_fields:$inventory(*)

, the inventory fields are missing from the query results. Why is this? How can I return the inventory fields without having to use a filter?