Dear Aspose Suport Team,
Thanks for your posting and using Aspose.Cells.
Aspose.Cells generates PDF as Microsoft Excel displays it in Print Preview. So if your Print Preview rendering matches with Aspose.Cells generated PDF, then it is a correct behavior.
If it does not match, then please provide us your source Excel file which you are converting to PDF so that we could replicate this issue at our end and log it in our database for a fix.
Please also download and try the latest version: Aspose.Cells
for Java v220.127.116.11 and see if it makes any difference.