It says:
In the translation editor interface you will see a section called "Downlaod files" with the field for the name and for the file URL. You can change it there according to your needs.
I enabled "Add separate download files for translations when translating products", here is a screenshot: hidden link
The problem is that I don't have this "Download files" section is translation editor interface. Check the screenshot.
Please send us access to your WordPress dashboard (website URL, login and password) and FTP credentials (important). I'll check and do some tests. - Please use the private field to send the sensitive data - do not post if you do not see it.
It would be better if you give me a test site rather than the live site.
IMPORTANT: Please backup a working copy of site files and database before.
Maybe I'll need to replicate your site locally. For this, please install these plugins: Duplicator:
https://wordpress.org/plugins/duplicator/
This will allow me to create a copy of your site and your content. Once the problem is resolved I will delete the local site. Please let me know if this is ok for you.