Duplicate user message shown three times when sending a prompt once

What version of the Codex App are you using (From “About Codex” dialog)?

26.506.31421

What subscription do you have?

ChatGPT Plus

What platform is your computer?

Darwin 25.3.0 arm64 arm

What issue are you seeing?

<img width="2048" height="1409" alt="Image" src="https://github.com/user-attachments/assets/66b661ab-de46-4f8d-ad7c-7ad3b9aee3ac" />

After I submitted a prompt once in a Codex conversation, the same user message appeared three times in the conversation UI.

The duplicated prompt text was:

遇到和图像相关的用HTML展示，例如这里展示Newton法的中间过程

In the UI, the first two duplicated messages stayed in a "thinking" state, while the third one eventually completed and showed a response. This made it look like the same prompt had been submitted multiple times, even though I only intended to send it once.

There was no explicit error message shown. The issue appears to be either a duplicate submission, retry, or conversation state synchronization problem.

I only clicked the send button once.

What steps can reproduce the bug?

I do not have a deterministic minimal reproduction yet, but this is what happened:

1. Open a Codex conversation.
2. Enter the following prompt:

遇到和图像相关的用HTML展示，例如这里展示Newton法的中间过程

1. Submit the prompt once.
2. Observe the conversation UI.

Actual result:

• The same user prompt appeared three times in the conversation.
• The first two duplicated entries stayed in a "thinking" state.
• The third entry eventually completed and produced a response.
• No explicit error message was displayed.

Session ID: Not available
Token limit usage: Not available / not shown
Context window usage: Not available / not shown

What is the expected behavior?

When I submit a prompt once, the Codex conversation should show exactly one user message and start exactly one corresponding assistant/Codex run.

If a retry happens internally due to network or server issues, the UI should not display duplicated user messages as separate conversation entries.

Additional information

_No response_