I noticed that you are using custom data source and the server responds with a DataSourceResult object. The array of data is stored in the Data property of the DataSource object and it is necessary to specify in which property of the response, the data is stored.
m.Id(field => field.OrderID);
m.Field(field => field.OrderID).Editable(false);
Or configure the the data source for AJAX binding.
Please refer to the following articles for better understanding: