It isn’t odd at all.
It was announced on the Cloudflare Developers Discord on 2023-02-02, that Cloudflare were in the process of rolling out translations for Cloudflare Turnstile.
See:
So regarding the language alone, there is nothing to worry about.
This one is correct.
If you are unhappy with the language, you need to consult your browser’s documentation for how to change the Accept-Language header that it provides to websites you’re visiting.
Firefox:
→ Changing the Language of Firefox Directly From the Browser | Mozilla L10N
Chrome:
→ Change Chrome languages & translate webpages - Computer - Google Chrome Help
“Add all the languages that you know” from there could be relevant.