I am facing same issue as mentioned in xlsx file content is corrupted after upgrading apache poi from 3.17 to 5.0.0 version.
I could open the Excel file generated successfully,but when it is transferred to a third party like exchange server or Power BI,it is throwing error saying the excel is corrupted.Please note I am using the following code
workbook.write(outputStream);
workbook.dispose();
outputStream.close();
But this is not resolving my issue.
Another difference I observed is some of the xml files have "standalone=no" when extracting it to xml.This is tracked under https://bz.apache.org/bugzilla/show_bug.cgi?id=67396
I am not sure if "standalone=no" is the reason for corruption.
Any input will be helpful.