We have tested this issue using latest version Aspose.Cells for .NET 18.10, but could not observe this issue. It seems that you are using some older version in your testing. Please give it a try using latest version and provide your feedback. Capture.PNG (15.6 KB) OutputOdsFile.zip (6.0 KB)
You may please try this scenario by converting the template XLSX file into ODS file using Excel 2013 and test if it opens fine in Excel 2013 or not. Send this ODS file (converted by Excel 2013) to us. Similarly an ODS file which is converted using Excel 2016 is attached here. Please test it using Excel 2013 in your environment and share the feedback (provide the snapshot as well). We will analyze the whole scenario and provide our feedback. OriFileByExcel2016.zip (4.7 KB)