Hey folks I need some support with "undetermined language" posting

Hey, thank you for this instance and this space, it is a great work.

1. One person tried to comment in one of my post, he received the "undetermined language" error, but selecting spanish he could comment successfully.
2. I am trying to comment to the same person, but when I try to avoid the "undetermined language" error (still present) choosing an option, there is no another option to pick.
3. I tried to modify the language of my community to see if this has effect in the comment mechanisms, but i can not select another option apart of "undetermined language", choosing spanish or english does not has effect.

What should I do?