Do you have the language set within the .tex document itself?
/selectlanguage{French}
Or something like that. You may need to /usepackage{babel}
as well or similar. I haven't played around much with LaTeX, so not sure this will work or not--but everything I've seen indicates that the TeX document language setting is what will key the LSP language setting.
On second thought, it looks like it probably isn't even vimtex or LSP related--probably just your vim settings. Try :set spelllang+=fr
Yes, just found out it’s not actually latex related, thought this because the spelling mistake text never showed up before, I try what you said later, thank you for your help !
Here is the solution in case someone came across this post in the future.To set the language of your LaTeX file, put :
\usepackage\[french]{babel}
and download the texlive-lang package corresponding :
sudo pacman -S texlive-lang
Glad you got it resolved! (Especially as, while I noted in my earlier reply, I don't use LaTeX currently, but I'm planning on switching over from asciidoc in the near future for reports and notes and occasionally I do need to write in French!)