I am sending the following events to Google Analytics 4:

gtag("event", "begin_checkout", {
  currency: "USD",
  value: 30.03,
  coupon: "SUMMER_FUN",
  items: [
    {
      item_id: "SKU_12345",
      item_name: "Stan and Friends Tee",
      affiliation: "Google Merchandise Store",
      coupon: "SUMMER_FUN",
      discount: 2.22,
      index: 0,
      item_brand: "Google",
      item_category: "Apparel",
      item_category2: "Adult",
      item_category3: "Shirts",
      item_category4: "Crew",
      item_category5: "Short sleeve",
      item_list_id: "related_products",
      item_list_name: "Related Products",
      item_variant: "green",
      location_id: "ChIJIQBpAG2ahYAR_6128GcTUEo",
      price: 10.01,
      quantity: 3
    }
  ]
});

and

gtag("event", "purchase", {
  currency: "USD",
  value: 30.03,
  coupon: "SUMMER_FUN",
  items: [
    {
      item_id: "SKU_12345",
      item_name: "Stan and Friends Tee",
      affiliation: "Google Merchandise Store",
      coupon: "SUMMER_FUN",
      discount: 2.22,
      index: 0,
      item_brand: "Google",
      item_category: "Apparel",
      item_category2: "Adult",
      item_category3: "Shirts",
      item_category4: "Crew",
      item_category5: "Short sleeve",
      item_list_id: "related_products",
      item_list_name: "Related Products",
      item_variant: "green",
      location_id: "ChIJIQBpAG2ahYAR_6128GcTUEo",
      price: 10.01,
      quantity: 3
    }
  ]
});

The events are captured by GA and I can see the parameters currency, value and coupon on the Event view:

When it come to the parameter items, it does not seem to be captured at all as I cannot see it anywhere, not on the Events view, and not on the E-commerce purchases view.

Does anyone have any idea what the issue is?