Extra Theme & Polylang: Translate title of Extra Module

Hi
I use the extra theme (from Elegant Themes) for a wordpress site and I would like to translate it to another language.
I use the polylang plugin and I have followed the steps from the following article https://goo.gl/8r39qv.
I can translate successfully pages, posts etc but I face the following issue.
As a home page I use an “Extra Category Layout” with some “Extra Modules” enabled.
The issue is that I cannot find a way to translate the “Primary Heading” of a custom title for an “Extra Module”.
For example, we need to support two languages (Greek and English) and we would like to have different titles based on the selected language.
Any hints are more than welcome.