The 'gpt-5.3-codex' model is not supported

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

26.814.41407

What subscription do you have?

Pro

What platform is your computer?

Microsoft Windows NT 10.0.26200.0 x64

What issue are you seeing?

When ChatGPT Desktop automatically moves a task from Chat to Work, it attempts to use gpt-5.3-codex and fails with:

The 'gpt-5.3-codex' model is not supported when using Codex with a ChatGPT account.

Manually starting the same type of task in Work works correctly. Work currently defaults to 5.6 Sol Medium and runs without an issue.

What steps can reproduce the bug?

Reproduction 1 – Chat → Work

Start a task in normal Chat.

ChatGPT displays a prompt saying the task would work better in Work and offers to shift to Work.

Accept the Shift to Work option.

A Work task is created.

It immediately fails with the gpt-5.3-codex error.

Reproduction 2 – Getting Started

Open the Getting Started panel in ChatGPT Desktop.

Select Summarize my inbox.

The resulting task attempts to run using gpt-5.3-codex.

The same unsupported-model error occurs.

What is the expected behavior?

Automatic Chat → Work handoffs and Getting Started tasks should use a currently supported Work model, rather than attempting to invoke gpt-5.3-codex.

Additional information

If I manually select Work, create a new task and enter the task directly, it works normally. The model shown is 5.6 Sol Medium, and there is a model selector available.

Issue appears specific to automatic Desktop workflows/handoffs

Start by reproducing the automatic Chat → Work handoff and the Getting Started “Summarize my inbox” flow in the Codex desktop app. Trace how each workflow selects gpt-5.3-codex versus the working 5.6 Sol Medium model. Done means both automatic workflows use a currently supported Work model and no longer fail with the unsupported-model error.