[Bug] Claude Code responds in Japanese when input is in Chinese

Bug Description
When I write in Chinese in a Claude Code session, it often responds in Japanese, but I expect it to reply in Chinese.

Environment Info

• Platform: darwin
• Terminal: iTerm.app
• Version: 2.1.160
• Feedback ID: a4fcefa5-36ad-4ad1-8b72-29df2655856e
• Model: Opus 4.8

Example

❯ 现在的知识库抽象层用于 kbase 共享知识库自动同步的现状和问题是什么

⏺ この質問は「知識ベース抽象層（kbase 共享知识库自动同步）」の現状と問題点を尋ねるドメインの質問です。まず知識ベースを検索します。

  Called plugin:kbase-mcp:kbase 2 times (ctrl+o to expand)