Fable 5 selection switches to Composer and re-enables Composer model

Support Bug Reports
, ,
1

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

When I enable only Claude Fable 5 Max in Settings > Models and select Fable 5 Max in the chat model picker, sending even a short test message changes the chat model display to Composer 2.5 Fast. After that, when I reopen Settings > Models, Composer is enabled again alongside Fable 5 Max.

This makes it unclear whether the request is actually routed to Fable 5 Max or Composer 2.5

Steps to Reproduce

  1. Open Cursor Settings > Models.
  2. Turn off all models except Claude Fable 5 Max.
  3. Open a new chat.
  4. Select Claude Fable 5 Max in the model picker.
  5. Send a short test message:

Expected Behavior

If Claude Fable 5 Max is the only enabled model and selected in the chat model picker, the request should either:

  • be routed to Claude Fable 5 Max, or
  • show an explicit error if Fable 5 Max is unavailable.

It should not silently switch to Composer 2.5 Fast or re-enable Composer without user consent

Operating System

Windows 10/11

Version Information

Version: 3.10.20 (user setup)
VS Code Extension API: 1.125.0
Commit: 23b9fb205fe595ea2be29da7214e19762d037fc0
Date: 2026-07-07T07:03:33.071Z
Layout: Agent Window
Build Type: Stable
Release Track: Default
Electron: 40.10.3
Chromium: 144.0.7559.236
Node.js: 24.15.0
V8: 14.4.258.32-electron.0
xterm.js: 6.1.0-beta.256
OS: Windows_NT x64 10.0.26200

For AI issues: which model did you use?

Selected model: Claude Fable 5 Max
Model shown after sending: Composer 2.5 Fast

The issue is that I selected Claude Fable 5 Max, but after sending the request the chat UI changed to Composer 2.5 Fast.

For AI issues: add Request ID with privacy disabled

7dddbc58-492c-418e-9dc9-4234edc6e93e

Additional Information

I temporarily disabled Privacy Mode only for this reproduction test.

Before sending the request, only Claude Fable 5 Max was enabled in Settings > Models, and the chat model picker showed Fable 5 Max.

After sending a short routing test, the chat UI changed to Composer 2.5 Fast. When I reopened Settings > Models, Composer was enabled again alongside Fable 5 Max.

The test was performed in an empty / throwaway workspace.

Does this stop you from using Cursor

No - Cursor works, but with this issue

Additional observation

After submitting this bug report and refreshing the Plan & Usage page, my API usage showed 100%.

This is confusing because the chat UI changed from Fable 5 Max to Composer 2.5 Fast, but API usage appears to have been consumed.

Please confirm from the Request ID whether the request was actually routed to Fable 5 Max, Composer 2.5 Fast, or another model, and why the API usage was consumed.

5

Hey, thanks for the detailed report and the Request ID. It helped me quickly verify everything.

About your request 7dddbc58-492c-418e-9dc9-4234edc6e93e, it was actually handled by Composer 2.5 Fast, not Claude Fable 5. That’s why the usage was charged to Composer, and the request never reached Fable.

Why this happened: Claude Fable 5 is a non-ZDR model, so you need to separately accept its data retention policy in the dashboard on cursor.com. This is not the same as Privacy Mode, turning off Privacy Mode consent won’t enable it. Also, Fable 5 only works in Max Mode. Until you accept the consent, the model is unavailable, and the client falls back to Composer 2.5 Fast. That’s the default model and it can’t be fully disabled, so it gets re-enabled when Fable is the only selected model.

To actually run Fable 5:

  • Open cursor.com, go to the dashboard, and accept the data retention policy for Claude Fable 5 using View Policy then Accept.
  • Restart Cursor.
  • Make sure Max Mode is enabled.

Also, I agree that silently switching to Composer without a clear error shouldn’t happen. I reported this internally as a separate issue.

If the model is still locked after accepting the policy, let me know. There might be a separate known bug there.

8

The same thing is happening to me with Sol. I started a session multiple times and every time it would start with Sol, think for 1-2 seconds, completely wipe the entire session and start a new one with Composer. This even happened when I turned Composer off in models. I tested this in multiple projects and it happened every time. This is for basic game creation, no security/medical or other triggers.

It’s also still happening with Fable 5 after accepting their policy twice and restarting Cursor. I also tried a “Hello world” prompt with Fable 5 after accepting the policy and restarting and it still changed to Composer.

9

Hey, thanks for the report, @Tara.

I’m going to split this into two parts, since this looks like two different cases.

Fable 5 after accepting the policy. The model staying locked and switching to Composer even after you accepted the data retention policy twice and restarted Cursor is a known bug on our side. Accept doesn’t always unlock Fable, and the banner or lock can come back. We don’t have an ETA for a fix yet. So it’s not on your end, and repeatedly clicking Accept won’t help right now.

Sol wiping the session and starting on Composer. I’d like to check this separately. Start on Sol → session gets wiped after 1 to 2 seconds → new session on Composer sounds different from the usual silent fallback. To verify where the request actually went, please send:

  • The Request ID from one of those Sol sessions. Turn Privacy Mode off for a moment, then go to the chat menu in the top-right > Copy Request ID
  • Your Cursor version and OS

About Composer coming back even when you turned it off. Composer 2.5 Fast is the default model and it can’t be fully disabled. It will be used as a fallback any time the selected model is unavailable. So it reappearing is a result of Fable or Sol not going through, not a separate issue.

One small ask. To avoid mixing your case with the original thread author’s report, please start a separate thread for your situation and include the Request ID and version there. That’ll make it easier to track your issue. Let me know how it goes.