Add and Save

   Not sure what the issue is, but your code above doesn't show where your 'person' value comes from.

In NorthwindIB, Order and Customer are related 0-1. The following code works fine, and reports 1 entity saved. (I've removed the statements that produce the output, as they're specific to my app.)

    public void Test1to1AddAndSave() {

      var customersQuery = _em1.Customers

        .Where(c => c.ContactTitle == "Sales Representative")

        .OrderBy(c => c.CompanyName);

      _em1.ExecuteQueryAsync<Customer>(customersQuery, GotCustomers, null);

    }

    private void GotCustomers(EntityQueryOperation<Customer> args) {

      Order newOrder = _em1.CreateEntity<Order>();

      newOrder.OrderDate = DateTime.Today;

      newOrder.Customer = args.Results.FirstOrDefault();

      _em1.SaveChangesAsync(op => {

        if (op.HasError) {

           // output error message

        }

        else {

           // output count of entities saved // reports "1"

        }

      }, null);

    }