macOS: Opening a Deep Research conversation created on chatgpt.com gets stuck on "Thinking" (@ Start)

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

ChatGPT 26.707.31428

What subscription do you have?

ChatGPT Go

What platform is your computer?

MacOS 26.5.1

What issue are you seeing?

After creating a Deep Research conversation on chatgpt.com, I installed the newly revamped/updated ChatGPT macOS desktop app (with codex and work integrated).

When browsing my existing chat history from the desktop app and opening that Deep Research conversation, the app does not load it correctly.

Instead, it opens a floating chat window that remains stuck on Thinking with @ Start shown at the bottom. The conversation never finishes loading.

What steps can reproduce the bug?

1. On chatgpt.com, create and complete a Deep Research conversation.
2. Install or update to the latest ChatGPT macOS desktop app.
3. Open the desktop app.
4. Click Chat in the left sidebar.
5. Open the Deep Research conversation that was created on the web.

What is the expected behavior?

The desktop app should either:

• open the conversation normally, or
• indicate that Deep Research conversations are not yet supported in the desktop app.

Additional information

Deep Research was not created from the desktop app.
It was created on chatgpt.com.
As far as I can tell, the current macOS app does not expose Deep Research as a feature yet.
The issue occurs when attempting to open an existing web-created Deep Research conversation from the desktop app.
Feedback already submitted through the ChatGPT macOS app.
Feedback ID: no-active-thread-019f4a32-77dd-7743-ac46-8a3e21bb8d59
attached screenshot for reference.

<img width="1536" height="1024" alt="Image" src="https://github.com/user-attachments/assets/d070d89f-48f6-40ea-b826-003d092df25a" />