Angular 2 / 4 Server Side Processing for Datatables not displaying data

Angular 4.2.4
Angular-Datatables 4.2.0
datatables 1.10.16
jQuery 3.2.1
Angular-cli 1.4.0
Node 6.11.4
npm 3.10.10

When the data returns back from the server, it's never populated into the table.

Html
<table datatable [dtOptions]="dtOptions"></table>

Component

ngOnInit() {

    this.dtOptions = {
        ajax: {
            url: "http://localhost:8880/nmets/api/manifest/search",
            type: 'POST',
            contentType: 'application/json; charset=UTF-8',
            error: function(xhr, error, code) { console.log(error); },
            success: function(result) {console.log(JSON.stringify(result))},
            data: function(data) {
                return JSON.stringify(data);
            }
        },
        columns: [

            { data: "departureTime", title: 'Departure Time', }

        ],
        processing: true,
        serverSide: true,
        pagingType: 'full_numbers',
        pageLength: 25,
    };
}

When the page loads I see the table header ("Departure Time") and I see the word "Processing...". I see the Post request and the server responds as follows (shortened):

Server Response

    {"draw":1,
    "recordsTotal":109,
    "recordsFiltered":109,
    "data":[
    {"departureTime":"2:18 pm"},
    {"departureTime":"2:55 pm"},
    {"departureTime":"8:54 pm"},
    {"departureTime":"9:10 pm"},
    {"departureTime":"12:28 am"},
    {"departureTime":"12:33 am"},
    ...
    ]}

I can see the result from the 'success' callback, but the table does not get populated, and the 'Processing...' also continues to display.

Any Ideas?

Thanks