Unable to link metafield to product options

[cviolette]

I'm receiving a "LINKED_METAFIELD_DEFINITION_NOT_FOUND" error when trying to link product options to a metafield with a `productOptionsCreate` query. I've verified both the product I'm trying to create options for and the metafield in question exist.

Following along with the example seen here: https://shopify.dev/docs/api/admin-graphql/2024-10/mutations/productOptionsCreate?example=Create+a+p... 

With the following query, I've verified the Product metafield exists:

query {
  metafieldDefinitions(first: 250, ownerType: PRODUCT) {
    edges {
      node {
        name
        namespace
        key
        type {
          name
        }
      }
    }
  }
}

Which returns:

{
  "data": {
    "metafieldDefinitions": {
      "edges": [
        {
          "node": {
            "name": "Colors",
            "namespace": "mynamespace",
            "key": "colors",
            "type": {
              "name": "list.metaobject_reference"
            }
          }
        }
        // TRUNCATED //
      ]
    }
  }
}

However, when using the same metafield namespace/key combination of mynamespace.colors, I get the "LINKED_METAFIELD_DEFINITION_NOT_FOUND" error.

mutation createOptions($productId: ID!, $options: [OptionCreateInput!]!) {
  productOptionsCreate(productId: $productId, options: $options) {
    userErrors {
      field
      message
      code
    }
    product {
      options {
        name
        linkedMetafield {
          namespace
          key
        }
        optionValues {
          name
          linkedMetafieldValue
        }
      }
    }
  }
}

// Variables:
{
  "productId": "gid://shopify/Product/########",
  "options": [
    {
      "name": "Colors",
      "linkedMetafield": {
        "namespace": "mynamespace",
        "key": "colors"
      }
    }
  ]
}

Returns:

{
  "data": {
    "productOptionsCreate": {
      "userErrors": [
        {
          "field": [
            "options"
          ],
          "message": "No valid metafield definition found at 'mynamespace.colors' for linked option",
          "code": "LINKED_METAFIELD_DEFINITION_NOT_FOUND"
        }
      ],
      "product": {
        "options": [
          {
            "name": "Title",
            "linkedMetafield": null,
            "optionValues": [
              {
                "name": "Default Title",
                "linkedMetafieldValue": null
              }
            ]
          }
        ]
      }
    }
  }
}