Entity references linked to a wrong referent On a Drupal 7 multilingual site, I have a content type containing a field_group containing itself entity references fields.

I haven't enabled the i18n submodule "Synchronize translations" ("i18n_sync").

I have a content in French:


contentFR


entityreferenceFR 1 
entityreferenceFR 2



I want to translate this content in Italian, so I translate the entity references first, like this :


entityreferenceIT 1 (translation of entityreferenceFR 1)
entityreferenceIT 2 (translation of entityreferenceFR 2)


Then, I translate "contentFR" in Italian, and associate my 2 Italian entityreferences to this new Italian content, like this:


contentIT (translation of contentFR)


entityreferenceIT 1
entityreferenceIT 2



Everything seems to go perfectly well, except that, when I go back to my French content, the references are the italian ones, like this:


contentFR


entityreferenceIT 1
entityreferenceIT 2



If I edit again the French content to set the French references instead of the Italian ones, the switch happens again in the other way:


contentIT


entityreferenceFR 1
entityreferenceFR 2



This is a live production site with 5 enabled languages. We've just enabled Italian and the issue exists only since then. Before, with other languages, everything was working well; the entity references were not linked to a wrong referent.

Also, I've seen this quite similar thread (Node translation syncing problem with entity references) but:


In my case, there's no synchronizing set on the reference field
There wasn't any answer given in the original thread


The enabled i18 modules are: Block languages, Multilingual content, Multilingual select, Path translation, String translation, Taxonomy translation, Translation redirect, Translation sets, and Variable translation. The disabled modules are: Field translation and Synchronize translations.

Do you have any idea why this happens?
I guess you need to enable entity translation for this field; it can be done in the field UI, after installing the Entity Translation module.