Fortunately, this is easy to fix.
Why does an AI Agent switch language?
LLMs determine their response language based on:- The language of the conversation
- The language of the available knowledge
- System-level instructions and context fields
This is expected behavior and not a bug.
How to fix it
To make sure your AI Agent consistently responds in the correct language, you need to set one specific field in English. Once this is done, the AI Agent will correctly interpret and apply all language instructions again.If your Agent was created some time ago already and still has Domain knowledge, please check the information below for Legacy Agents.
- Open your Agent.
- Navigate to AI Agent settings.
- Translate the personality to English (one of the other fields works too).
- Save your changes.
For Legacy Agents
- Open your Agent.
- Navigate to Domain knowledge.
- Translate the personality to English (one of the other tabs works too).
- Save your changes.
A Legacy Agent includes Domain knowledge. You can recognize a a Legacy Agent by opening the Agent and checking if the Domain knowlegde is visible in the left-hand menu.

