Datatables error after adding row with Editor

You can ignore my previous question if you can answer this one, as this is the issue I'm trying to solve. I'm getting this error after adding a row with Editor to a DOM-sourced table that uses data-order attributes to order data:

DataTables warning: table id=datesTable - Requested unknown parameter '[object Object]' for row 44, column 0. For more information about this error, please see http://datatables.net/tn/4

Here's a sample table:

<table id="datesTable">
    <thead>
        <tr>
            <th colspan="5">Active Time Periods</th>
            <th colspan="1">
                <button type="button" id="addDatesButton">Add</button>
            </th>
        </tr>
        <tr>
            <th>Start Date</th>
            <th>End Date</th>
            <th>Last Updated</th>
            <th>By</th>
            <th>Created</th>
            <th>By</th>
        </tr>
    </thead>
    <tbody>
            <tr id="31845069">
                <td data-order="1968-05-01T00:00:00" class="dws-table-edit-field">05/01/1968</td>
                <td data-order="1968-10-31T00:00:00" class="dws-table-edit-field">10/31/1968</td>
                <td data-order="1999-11-14T14:49:35">11/14/1999</td>
                <td>DATE TRANSFER</td>
                <td data-order="1999-11-14T14:49:35">11/14/1999</td>
                <td>DATE_TRANSFER</td>
            </tr>
            <tr id="31845070">
                <td data-order="1969-05-01T00:00:00" class="dws-table-edit-field">05/01/1969</td>
                <td data-order="1969-10-31T00:00:00" class="dws-table-edit-field">10/31/1969</td>
                <td data-order="1999-11-14T14:49:35">11/14/1999</td>
                <td>DATE TRANSFER</td>
                <td data-order="1999-11-14T14:49:35">11/14/1999</td>
                <td>DATE_TRANSFER</td>
            </tr>
            <tr id="31845071">
                <td data-order="1970-05-01T00:00:00" class="dws-table-edit-field">05/01/1970</td>
                <td data-order="1970-10-31T00:00:00" class="dws-table-edit-field">10/31/1970</td>
                <td data-order="1999-11-14T14:49:35">11/14/1999</td>
                <td>DATE TRANSFER</td>
                <td data-order="1999-11-14T14:49:35">11/14/1999</td>
                <td>DATE_TRANSFER</td>
            </tr>
            <tr id="31845072">
                <td data-order="1971-05-01T00:00:00" class="dws-table-edit-field">05/01/1971</td>
                <td data-order="1971-10-31T00:00:00" class="dws-table-edit-field">10/31/1971</td>
                <td data-order="1999-11-14T14:49:35">11/14/1999</td>
                <td>DATE TRANSFER</td>
                <td data-order="1999-11-14T14:49:35">11/14/1999</td>
                <td>DATE_TRANSFER</td>
            </tr>
            <tr id="31845073">
                <td data-order="1972-05-01T00:00:00" class="dws-table-edit-field">05/01/1972</td>
                <td data-order="1972-10-31T00:00:00" class="dws-table-edit-field">10/31/1972</td>
                <td data-order="1999-11-14T14:49:35">11/14/1999</td>
                <td>DATE TRANSFER</td>
                <td data-order="1999-11-14T14:49:35">11/14/1999</td>
                <td>DATE_TRANSFER</td>
            </tr>
            <tr id="31845074">
                <td data-order="1973-05-01T00:00:00" class="dws-table-edit-field">05/01/1973</td>
                <td data-order="1973-10-31T00:00:00" class="dws-table-edit-field">10/31/1973</td>
                <td data-order="1999-11-14T14:49:35">11/14/1999</td>
                <td>DATE TRANSFER</td>
                <td data-order="1999-11-14T14:49:35">11/14/1999</td>
                <td>DATE_TRANSFER</td>
            </tr>
    </tbody>
</table>

And relevant Javascript:

var datesTable;

function updateRowDateCellsAttr(rowId) {
    var dtCell = datesTable.cell('#' + rowId, 0); // get first cell of row
    $(dtCell.node()).attr('data-order', '2020-01-01T00:00:00');  // hardcoded data-order value
}

$(function () {
    var datesEditor = new $.fn.dataTable.Editor({
        ajax: {
            url: '/api/rodates'
        },
        table: '#datesTable',
        fields: [
            { label: 'Start Date', name: 'StartDate', type: 'datetime', format: 'MM/DD/YYYY' },
            { label: 'End Date', name: 'EndDate', type: 'datetime', format: 'MM/DD/YYYY' }
        ],
        formOptions: {
            main: {
                buttons: [
                    {
                        text: 'Cancel',
                        className: 'btn-primary mr-2',
                        action: function () {
                            this.close();
                        }
                    },
                    {
                        text: 'Save',
                        className: 'btn-primary',
                        action: function () {
                            this.submit();
                        }
                    }
                ],
                title: 'Edit Dates',
                submit: 'allIfChanged'
            }
        }
    });

    datesEditor.on('create', function (e, json, data, id) {
        updateRowDateCellsAttr(id);
    });

    $('#datesTable').on('click', '.dws-table-edit-field', function (e) {
        datesEditor.edit($(this).closest('tr'));
    });

    $('#addDatesButton').click(function () {
        datesEditor.create();
    });

    datesTable = $('#datesTable').DataTable({
        dom: 't',
        order: [[0, 'desc']],
        columns: [
            {
                data: {
                    _: 'StartDate',
                    type: '@data-order',
                    sort: '@data-order'
                }
            },
            {
                data: {
                    _: 'EndDate',
                    type: '@data-order',
                    sort: '@data-order'
                }
            },
            {
                data: {
                    _: 'LastUpdateDate',
                    type: '@data-order',
                    sort: '@data-order'
                }
            },
            { data: "LastUpdateUserId" },
            {
                data: {
                    _: 'CreationDate',
                    type: '@data-order',
                    sort: '@data-order'
                }
            },
            { data: "CreationUserId" }
        ]
    });

});

And the JSON response containing the data to add to the row:

{"data":[{"DT_RowId":"32016819","StartDate":"05/01/2019","EndDate":"10/31/2019","LastUpdateDate":"10/17/2019","CreationDate":"10/17/2019","LastUpdateUserId":"tinbebxnni","CreationUserId":"tinbebxnni"}],"error":null,"fieldErrors":[]}