Google assistant cannot detect language

I'm using both English and French as my assistant language. But sometimes, even often, I tun into issues:

-when I speak french to it, it answer in english, and I have to say "speak french" to solve it (same issue in the other way)

-when I have routines where he is supposed make an announcement in english, he will speak french trying to read it with a terrible and ridiculous accent

-when it's in english, and I receive a message in French, the hand-free feature that read notification will read it in English trying to read it with another terrible accent.

I really feel google assistant is good, but this issue I face it way too often, and it just ruin my experience