[Risolto] Linking of different languages with english via all import export plugin

Background of the issue:
I am trying to link French language to English on my site link nascosto using the All Import Export plugin. Dutch language is already imported and linked successfully.

Symptoms:
Facing an issue with linking French language to English, while Dutch language linked without problems.

Questions:
How can I link the French language to English using the All Import Export plugin?
Why is the French language not linking to English while Dutch linked successfully?