Devexpress report label not showing value

Question

Can anyone tell me why same bounded xrLabel in details showing correct value but in page or report header label value is null.

If I set null text value on run time null text value is displayed in page header. In report detail value is set to db value.

Happy to give more details if necessary.

Thanks

EDIT : code for opening print preview

    private void barItemPrint_ItemClick(object sender, DevExpress.XtraBars.ItemClickEventArgs e)
    {
        try
        {
            int _rId = ((Raspored)rasporedBindingSource.Current).Id;

            RasporedReport1 report = new RasporedReport1();

            report.DataSource = _context.RasporedStavke.Where(r => r.Id == _rId);

            ReportPrintTool printTool = new ReportPrintTool(report);
            printTool.ShowPreview(UserLookAndFeel.Default);

        }
        catch
        {
            throw;
        }

    }