Data Query helper function { process } sorting problem

I am using the helper function process, like this example

https://www.telerik.com/kendo-react-ui/components/dataquery/bulk-operations/ 

const data = [
    { "productName": "Chai", "unitPrice": 18, "unitsInStock": 39, "discontinued": false,
      "category": { "categoryName": "Beverages" }
    },
    { "productName": "Chang", "unitPrice": 19, "unitsInStock": 17, "discontinued": false,
      "category": { "categoryName": "Beverages" }
    },
    { "productName": "Aniseed Syrup", "unitPrice": 10, "unitsInStock": 13, "discontinued": false,
      "category": { "categoryName": "Condiments" }
    },
    { "productName": "Cajun Seasoning", "unitPrice": 22, "unitsInStock": 53, "discontinued": false,
      "category": { "categoryName": "Condiments" }
    },
    { "productName": "Gumbo Mix", "unitPrice": 21.35, "unitsInStock": 0, "discontinued": true,
      "category": { "categoryName": "Condiments" }
    }
];

const result = process(data, {
    group: [{
        field: 'category.categoryName',
        aggregates: [
            { aggregate: "sum", field: "unitPrice" },
            { aggregate: "sum", field: "unitsInStock" }
        ]
    }],
    sort: [{ field: 'productName', dir: 'desc' }],
    filter: {
        logic: "or",
        filters: [
            { field: "discontinued", operator: "eq", value: true },
            { field: "unitPrice", operator: "lt", value: 22 }
        ]
    }
});

I am expecting the result like the example

{
  "data": [
    { "aggregates": {
        "unitPrice": { "sum": 53.35 },
        "unitsInStock": { "sum": 66 }
      },
      "field": "category.categoryName",
      "items": [
        { "productName": "Gumbo Mix", "unitPrice": 21.35, "unitsInStock": 0, "discontinued": true,
          "category": { "categoryName": "Condiments" }
        },
        { "productName": "Aniseed Syrup", "unitPrice": 10, "unitsInStock": 13, "discontinued": false,
          "category": { "categoryName": "Condiments" }
        }
      ],
      "value": "Condiments"
    },
    {
      "aggregates": {
        "unitPrice": { "sum": 37 },
        "unitsInStock": { "sum": 56 }
      },
      "field": "category.categoryName",
      "items": [
        { "productName": "Chang", "unitPrice": 19, "unitsInStock": 17, "discontinued": false,
          "category": { "categoryName": "Beverages" }
        },
        { "productName": "Chai", "unitPrice": 18, "unitsInStock": 39, "discontinued": false,
          "category": { "categoryName": "Beverages" }
        }
      ],
      "value": "Beverages"
    }
  ],
  "total": 4
}

But I actually got this, which is not ordering by the product name, but order by the category name and then product name

{
  data: [
    {
      aggregates: {
        unitPrice: {
          sum: 37,
        },
        unitsInStock: {
          sum: 56,
        },
      },
      field: "category.categoryName",
      items: [
        {
          productName: "Chang",
          unitPrice: 19,
          unitsInStock: 17,
          discontinued: false,
          category: {
            categoryName: "Beverages",
          },
        },
        {
          productName: "Chai",
          unitPrice: 18,
          unitsInStock: 39,
          discontinued: false,
          category: {
            categoryName: "Beverages",
          },
        },
      ],
      value: "Beverages",
    },
    {
      aggregates: {
        unitPrice: {
          sum: 31.35,
        },
        unitsInStock: {
          sum: 13,
        },
      },
      field: "category.categoryName",
      items: [
        {
          productName: "Gumbo Mix",
          unitPrice: 21.35,
          unitsInStock: 0,
          discontinued: true,
          category: {
            categoryName: "Condiments",
          },
        },
        {
          productName: "Aniseed Syrup",
          unitPrice: 10,
          unitsInStock: 13,
          discontinued: false,
          category: {
            categoryName: "Condiments",
          },
        },
      ],
      value: "Condiments",
    },
  ],
  total: 4,
}

How can I achieve the result in the example?