[ChatGPT Web][Windows/Chrome] Backspace on an @ plugin mention can make the chat/composer disappear

What issue are you seeing?

On ChatGPT Web (chatgpt.com), the conversation/composer can disappear or reset when Backspace is used while editing or removing an @ plugin/skill mention.

The strongest reproduction is after a plugin prompt has already completed: start the next prompt, invoke the @ picker again, select or begin editing a plugin/skill mention, then press Backspace. The chat/composer UI can disappear unexpectedly.

Normal typing by itself is not the main trigger. The issue appears tied to the @ mention/autocomplete/token state plus Backspace.

Steps to reproduce

1. Open an existing conversation on ChatGPT Web.
2. Click the message composer.
3. Type @ and select a plugin/skill from the picker.
4. Submit the prompt and wait for the response/plugin execution to finish.
5. Click the composer to start the next prompt.
6. Type @ again and select or partially select a plugin/skill mention.
7. Press Backspace to edit/remove the mention or text around it.
8. The composer/chat UI may disappear, reset, or collapse.
9. Repeating the @ -> plugin selection -> Backspace sequence reproduces the problem.

Expected behavior

Backspace should delete text or remove the selected @ mention normally. The composer should stay mounted and focused, and the conversation should remain visible.

A completed prior plugin invocation should not leave stale composer/mention state that affects the next prompt.

Actual behavior

Pressing Backspace while editing/removing an @ plugin/skill mention can destabilize the composer and cause the chat/composer UI to disappear or reset, interrupting message composition.

Environment

• Product: ChatGPT Web (chatgpt.com)
• OS: Windows 10
• Browser: Google Chrome 152
• Device: Desktop
• Observed: 2026-09-10

Frequency

The issue is repeatedly reproducible around the @ plugin/skill mention flow, especially after a previous plugin prompt has completed.

Public reproduction/reference

I created a public issue with the same reproduction details here:

https://github.com/zrt219/chatbot/issues/1

A screen recording was also captured showing the failure being reproduced.

Notes for investigation

The failure may be around the rich composer mention lifecycle rather than normal text input. Useful areas to inspect would be mention-token deletion, autocomplete teardown, stale state after a completed plugin turn, keyboard/input event handling, focus restoration, or an unexpected composer unmount/remount.

This report is for ChatGPT Web, not the Codex CLI.

The report identifies ChatGPT Web rather than the Codex CLI and names no repository files, tests, or entry points. Confirm that the issue belongs in this repository before looking for an applicable frontend component; done would require a reproducible fix that keeps the composer and conversation visible during the described Backspace flow.