Selected Model switches after leaving agent chat and returning

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1

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

After opening a new chat, choosing Composer 2.5, begin chat, switching to another chat for information, returning to new chat, the model is returned to Grok 4.6.

Steps to Reproduce

For starters, my default model is Grok 4.6 High (non-fast)
I plan in chat #1.
When plan is complete, I open plan #2, start my implementation chat and change default model to Composer 2.5
Switch back to plan #1 to remember the plan name for tagging in the new chat.
Return to new chat, type in the plan reference and notice Grok 4.6 High is the selected model even though I previously changed it to Composer 2.5

Expected Behavior

In a chat, once a model is selected, it should stick even if you leave the chat and return.

Operating System

Linux

Version Information

Version: 3.17.21
VS Code Extension API: 1.128.0
Commit: 8f2a112cb2845a97b75fd932ea5c470579ca4060
Date: 2026-08-25T01:05:08.089Z
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.291
OS: Linux x64 7.0.0-30-generic

Does this stop you from using Cursor

No - Cursor works, but with this issue

7

Hey @C_ST , thanks for the clear repro!

This isn’t intended behavior, and it’s nothing in your setup. A brand-new chat with no message sent yet gets re-created when you tab away and back, which drops the Composer 2.5 you just picked.

Quickest fix: type your plan reference (or anything) into the new chat before switching over to plan #1 - once it has text, the model sticks. For a durable fix, set Settings → Agents → Conversation → Default Model → “Last Used” so new chats keep your last pick.

We’ve let the team know. I’ll post here if there’s an update.