Cannot stop Excel Parser Add-in in Passolo 2015 from writing translations into the source file rather than the specified target location

I have an Excel 2013 spreadsheet with columns of data to be translated. I have specified different target locations because I want translations to be written into a copy of the Excel file in a different folder location. Unfortunately, although the target file is written, the Excel 2013 sometimes writes the translation back into the original file instead of the target file. This issue seems to be intermittent, possibly whenever I update the source. Sometimes it behaves correctly and writes the target file correctly and sometimes the original file is updated.

Is there anything I can do?