VS Code new thread titles contain garbled text and unrelated extra English fragments

What version of Codex is running?

VS Code extension openai.chatgpt version 26.5304.20706

What platform is your computer?

Windows 11 Pro 22H2 (build 22621.2861), VS Code 1.110.1 (x64)

What issue are you seeing?

When I start a new chat/thread from the VS Code extension, the auto-generated title is often corrupted. The expected Chinese title is followed by unrelated English text or error-like fragments.

Examples from the sidebar:

• 根据说明安装需求...}istine The title has a str
• 检查并安装本机Git...}ubby questionable? Need
• 设置 VSCode 显示中文...}ાશે wait need remove

<img width="475" height="440" alt="Image" src="https://github.com/user-attachments/assets/53f70c4a-483e-4565-be39-dc457168cf20" />

Steps to reproduce

1. Open the Codex sidebar in VS Code.
2. Start a new thread in Chinese.
3. Wait for the extension to auto-generate the thread title.
4. Look at the thread list in the sidebar.

Expected behavior

The thread title should contain only a clean summary of the conversation.

Actual behavior

The title contains garbled characters and unrelated extra English text after the intended Chinese summary. The malformed title is persisted and remains visible in the thread list.

Additional information

• I can reproduce this across multiple newly created threads.
• I have a screenshot showing the problem.
• I found the malformed titles persisted in VS Code workspace storage (state.vscdb.backup), which suggests the bad value is being saved, not only rendered incorrectly.
• I have not confirmed the root cause; this report is based on the observed behavior above.