为什么Google对产品效果退款的分析为零？

Question

使用示例代码：

gtag('event', 'refund', {
  "transaction_id": "79.18502354114992",
  "affiliation": "Google online store",
  "value": 23.07,
  "currency": "USD",
  "tax": 1.24,
  "shipping": 0,
  "items": [
    {
      "id": "P12345",
      "name": "Android Warhol T-Shirt",
      "list_name": "Search Results",
      "brand": "Google",
      "category": "Apparel/T-Shirts",
      "variant": "Black",
      "list_position": 1,
      "quantity": 2,
      "price": '2.0'
    },
    {
      "id": "P67890",
      "name": "Flame challenge TShirt",
      "list_name": "Search Results",
      "brand": "MyBrand",
      "category": "Apparel/T-Shirts",
      "variant": "Red",
      "list_position": 2,
      "quantity": 1,
      "price": '3.0'
    }
  ]
});

示例网址：https://developers.google.com/analytics/devguides/collection/gtagjs/enhanced-ecommerce#measure_refunds

退款后，销售业绩退款金额显示为正常，但产品业绩退款金额为零。如何解决这个问题？

假设我退还了商品总金额50，销售业绩退款金额显示为50，产品绩效显示0。我需要销售业绩退款金额为50，产品绩效退款金额也为50