[iOS/macOS] GPT-5.6 Luna Max appears as Luna Medium in the same remote session

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

iOS ChatGPT app: 1.2026.202 - macOS ChatGPT/Codex app: 26.727.51351

What subscription do you have?

Pro

What platform is your computer?

iOS: 26.5.2 and macOS Tahoe: 26.5.2 (Darwin 25.5.0 arm64 arm)

What issue are you seeing?

When I select GPT-5.6 Luna with Max reasoning effort in the ChatGPT iOS app, the same remote session is displayed as 5.6 Luna Medium when opened in the macOS ChatGPT app.

This creates uncertainty about whether:

• Max is active but displayed incorrectly; or
• the session is actually downgraded to Medium when opened on macOS.

What steps can reproduce the bug?

1. Sign in to the same Pro account on iOS and macOS.
2. On iOS, select GPT-5.6 Luna with Max reasoning effort.
3. Start or continue a remote session.
4. Open the same session in the macOS ChatGPT app.
5. Inspect the model and reasoning-effort indicator.

What is the expected behavior?

The same remote session should preserve and display the same model and reasoning effort on both platforms:

GPT-5.6 Luna + Max

If Max is unavailable on macOS, the application should clearly state that limitation. It should not silently display the session as Medium.

Additional information

_No response_