Under WPML settings, and search through all the settings and change the fields that had "content" in it to translatable.
Then:
1- Edit the product in the original language
2- Do a slight change somewhere (add space or dot anywhere)
3- Hit save (this will trigger WPML to detect that you need to update the translation for the product)
4- Retranslate it
5- Do you see those fields as translatable? Relevant Documentation:
