Why are changes not saved in kendoGrid using custom editor?

Question

ASP.NET

Created a simple object model with products and categories:

public class Product
    {
        public int Id { get; set; }
        public string Name { get; set; }
        public virtual Category Category { get; set; }
    }
    public class Category
    {
        public int Id { get; set; }
        public string Name { get; set; }
    }

Using KendoUI, I made a grid for displaying and editing products:

$("#productGrid").kendoGrid({
        dataSource: {
            type: "odata",
            transport: {
                read: {
                    url: "/odata/Product",
                    dataType: "json",
                    data: {
                        $select: "Id, Name, Category/Name",
                        $expand: "Category"
                    }
                },
                create: {
                    url: "/odata/Product",
                    type: "POST",
                    dataType: "json",
                    contentType: "application/json"
                },
                update: {
                    url: function (data) {
                        return "/odata/Product(" + data.Id + ")";
                    },
                    type: "PUT",
                    dataType: "json",
                    contentType: "application/json"
                },
                destroy: {
                    url: function (data) {
                        return "/odata/Product(" + data.Id + ")";
                    },
                    type: "DELETE",
                    dataType: "json"
                },
                parameterMap: function (options, operation) {
                    var paramMap = kendo.data.transports.odata.parameterMap(options);

                    delete paramMap.$format;

                    if (operation !== "read" && options) {
                        delete paramMap.$inlinecount;
                        return JSON.stringify(paramMap);
                    }

                    return paramMap;
                },
            },
            schema: {
                data: function (data) {
                    return data.value;
                },
                total: function (data) {
                    return data['odata.count'];
                },
                model: {
                    id: "Id",
                    fields: {
                        Id: { type: "number", editable: false },
                        Name: { type: "string" },
                        Category: { defaultValue: { Name: "DefCategory" } },
                    }
                }
            },
            pageSize: 10,
            serverPaging: true,
            serverFiltering: true,
            serverSorting: true,
            serverGrouping: true
        },
        height: 550,
        sortable: true,
        editable: "inline",
        toolbar: ["create"],
        pageable: {
            refresh: true,
            pageSizes: true,
            buttonCount: 5,
        },
        columns: [
            { field: "Name", title: "Name", width: 200 },
            { field: "Category", title: "Categ", template: "#=Category.Name#", editor: categoryEditor },
            { command: ["edit", "destroy"], title: " " },
        ]
    });

To edit the category, I made a custom editor:

function categoryEditor(container, options) {
        $('<input required data-text-field="Name" data-value-field="Id" data-bind="value:' + options.field + '"/>')
            .appendTo(container)
            .kendoDropDownList({
                dataTextField: "Name",
                dataValueField: "Id",
                autoBind: false,
                dataSource: {
                    type: "odata",
                    schema: {
                        data: "value",
                        total: "['odata.count']",
                        model: {
                            id: "Id",
                            fields: {
                                Id: { editable: false, type: "number" },
                                Name: { type: "string", nullable: false }
                            }
                        }
                    },
                    transport: {
                        read: {
                            url: "/odata/Category",
                            dataType: "json",
                            contentType: "appliction/json"
                        }
                    }
                }
            });
    }

Ordinary text data is successfully changed, but the category first changes, but after updating the data, it becomes clear that the new value did not get into the database.