AI 突然開始用法文亂回答，我查了超久才發現真相——你的 AI 可能也有這問題

I built a RAG system that needs to answer in German or English depending on the query language. Sounds simple. It was not. The source documents are mostly in German but some contain French legal terminology, Latin phrases, and occasional English citations. What kept happening was the LLM would start answering in German, hit a French passage in the context, and just.. switch to French mid-paragraph. Sometimes it would blend German and French in the same sentence. Once it answered entirely in Ita