Search bar does not work in Chinese version but works fine in English version

The search bar is not working in the Chinese version but works perfectly fine in the English version, what is the issue?

After trying to search in the Chinese version, it either stays on the same page, or it shows the “Not Found” page. But when I use the search bar on the “Not Found” page, it works and shows searching results normally.

The site uses Elementor as the editor, and Polylang for managing languages if it’s related.

The page I need help with: [log in to see the link]