groupdocs version: 18.7 for Java
os: Ubuntu 14.04.5 LTS
If you have merged cells with more then one line of text in an XLSX file and convert to pdf, groupdocs will only render the first line of the merged cells. see attached document. this document rendered fine with libreoffice.
This issue is reproduced at our end. Hence, it has been logged in our internal issue trackign system with ID : CONVERSIONJAVA-544. We’ll notify you as we have any further update on it.