✅ WPF. Instance with the same key value for {'Id'} is already being tracked

using (ProfitCalculatorDataBaseContext db = new ProfitCalculatorDataBaseContext())
{
    var ord = from order in db.Orders
              where order.Completed == 0
              select new OrdView
              {
                  oId = order.Id,
                  oNum = order.Num,
                  oData = order.Data,
                  oCustomersMail = order.CustomersMail,
                  oStartPoint = order.StartPoint,
                  oFinalPoint = order.FinalPoint,
                  oTrackNumber = order.TrackNumber,
                  oOrderStatus = order.OrderStatus,
                  oComment = order.Comment,
                  oMoneyPerOrder = order.MoneyPerOrder,
                  oCompleted = order.Completed
              };
    activeOrdersGrid.ItemsSource = ord.ToList();
}

using (ProfitCalculatorDataBaseContext db = new ProfitCalculatorDataBaseContext())
{
    var ord = from order in db.Orders
              where order.Completed == 1
              select new OrdView
              {
                  oNum = order.Num,
                  oData = order.Data,
                  oCustomersMail = order.CustomersMail,
                  oStartPoint = order.StartPoint,
                  oFinalPoint = order.FinalPoint,
                  oTrackNumber = order.TrackNumber,
                  oOrderStatus = order.OrderStatus,
                  oComment = order.Comment,
                  oMoneyPerOrder = order.MoneyPerOrder,
                  oCompleted = order.Completed
              };
    completedOrdersGrid.ItemsSource = ord.ToList();