As a follow-up, I compiled the PO files with Passolo 2016 and converted it to PDF using the following procedure and now everything that was translated shows up translated.
The process I am using is as follows: Using po4a-translate and the translated PO files, the ASCII docs were translated. After the translation, the ASCII doc files were converted into PDF using asciidoctor-pdf.
Problem solved and now I know to use 2016 for PO files. This might help someone else.