how to desactivate the automatic enrollment to an offering?

Summary:

Hello,

We have created a specialization with courses and in these courses we have offering in 3 differents languages.

When we assign the specialization and the the learner enroll in the course , he cannot chose the language of the offering.He is automatically enrolled in the offering in the language he is currently using the system.
He cannot choose between the 3 languages.

However if the Learner access the course direclty from the self service catalog , then he can choose the offering in the language that he wants.

Could you please provide guidance on how to desactivate this automatic enrollment to a specific offer?