Shopify Dynamic Facebook Ads Product Feed does not sync Product Type

We have Facebook connected to our Shopify store using the built-in Facebook Channel in Shopify. Everything is syncing except for one very important item, Product Type. For whatever reason, Shopify does not sync the Product Type field with Facebook. We tried using a paid app like Simprosys or Flexify to add the missing Product Type data via a supplemental feed in Facebook, but that did not work because Product Type is one of the fields that cannot be updated via supplemental feed.

Does anyone know of a way to get this working?

Mark