Can you send us your Excel file so that we can take a look at it?
Perhaps your sheet defines a print area that contains just that column “A”.
If that’s the case, you’ll need to either increase the print area or remove it:
var worksheet = workbook.Worksheets.ActiveWorksheet;
var printArea = worksheet.NamedRanges["_xlnm.Print_Area"];
if (printArea != null)
{
Console.WriteLine($"The cell range of print area: {printArea.Range.Name}");
// ...
}
Or perhaps you need to specify these options:
var worksheet = workbook.Worksheets.ActiveWorksheet;
worksheet.PrintOptions.FitWorksheetWidthToPages = 1;
worksheet.PrintOptions.FitWorksheetHeightToPages = 1;