Thanks for providing us the sample code.
After an initial test using your code we found the issue as you have described regarding Spreadsheetml file generated by Aspose.Cells for Java. We will figure it out soon.
Your issue has been logged into our issue tracking system with an issue id: CELLSJAVA-11911.
Thank you for considering Aspose.
Please try the attached latest version of Aspose.Cells. We have fixed your mentioned issue.
Thank You & Best Regards,
It seems to work.