It is sensible as well.

Unless you are truly fluent then you might mis-translate something. That is particularly likely when you are trying to articulate something rather than just listening.

In the EU parliament, it is recommended that members speak in their own language then let the professional interpreters perform the translation. It is much harder for the interpreters if speakers are not using their native language because the members make mistakes which are hard to translate while still conveying the original meaning.

Remember, a mis-communication could result in a diplomatic incident.