PPTX file exported from Tomcat works but exported from WAS is corrupted

Recently we started using PPTX Exporter.  We are using JasperReports 6.5.1 and everything works well on Tomcat8 running on JDK8.

When we used WAS8, WAS8.5 and WAS9,  the report exeported in PPTX without any error.  But when I try to open that file with Microsoft Powerpoint it shows following error:

Clicking on Repair button repairs the file and opens it but all pages are blank.

When I open this file with Open Office  Impress it works well.  What could be the issue with WAS?

I have attached sample exported file also for review.