Conversation history was lost between the ChatGPT Web and Desktop applications

What issue are you seeing?

A complete working conversation disappeared after switching between the ChatGPT Web application and the unified ChatGPT/Codex desktop application.

The conversation contained several hours of work, including product evaluations, generated documents, images, worksheets, and planning notes.

After moving between the Web and Desktop clients, the conversation was no longer available in either client.

The conversation appears to have been lost rather than simply failing to synchronize.

What steps can reproduce the bug?

1. Work in a long ChatGPT conversation containing generated documents, images, and extensive discussion.
2. Switch between the ChatGPT Web application and the unified ChatGPT/Codex desktop application.
3. Continue working in both clients.
4. Observe that the conversation eventually disappears from both clients.

In this case the conversation contained product evaluations, generated spreadsheets, generated images, and planning documents before disappearing.

What is the expected behavior?

Conversation history should synchronize completely between all ChatGPT clients.

No messages, generated files, images, or conversation history should be lost when switching between the Web application and the Desktop application.

If synchronization conflicts occur, the conversation should be preserved rather than disappearing.

Additional information

Platform

ChatGPT Web
Unified ChatGPT/Codex Desktop Application

Impact

This resulted in the apparent loss of an entire working session containing several hours of consulting work.

The missing conversation included generated documents, product evaluations, planning discussions, images, spreadsheets, and product recommendations.

Data loss is significantly more disruptive than delayed synchronization because users cannot determine whether the conversation still exists or has been permanently lost.

This appears to be related to synchronization between the Web and Desktop applications but is distinct from issues involving generated file attachments.