Subagents ignore selected model (Composer 2.5) and run as Cursor Grok 4.6 High in Multitask / parallel sessions

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1

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

@deanrie

When I run a parallel/Multitask agent session with Composer 2.5 selected in the model picker, spawned subagents still start as Cursor Grok 4.6 High.

The parent chat correctly shows Composer 2.5, but the subagent tile labels the model as Cursor Grok 4.6 High. This has been happening intermittently in chat for a while. Because Grok 4.6 High is much more expensive than Composer 2.5, this is burning usage I did not intend to spend.

Screenshot attached shows parent picker on Composer 2.5 while subagent “Start local dev server” is running as Cursor Grok 4.6 High.

Steps to Reproduce

  1. Open Cursor IDE Agent chat / Agent Window.
  2. Enable Multitask (parallel session).
  3. Set the model picker to Composer 2.5.
  4. Prompt the agent to do work that spawns a subagent (e.g. start local dev server / coordinate tasks).
  5. Observe the subagent tile: it shows Cursor Grok 4.6 High instead of Composer 2.5.

Expected Behavior

Subagents should inherit the model selected in the parent chat model picker (Composer 2.5), or use an explicitly chosen subagent model if one is set. They should not silently fall back to / run as Cursor Grok 4.6 High.

Actual:

  • Parent model picker: Composer 2.5
  • Spawned subagent model label: Cursor Grok 4.6 High
  • Result: unexpected usage consumption

Screenshots / Screen Recordings

Screenshot 2026-08-29 at 4.53.57_AM.png
Screenshot 2026-08-29 at 4.53.57_AM.png1700×1380 155 KB

Operating System

MacOS

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: Darwin arm64 25.6.0

For AI issues: which model did you use?

Selected parent model: Composer 2.5
Subagent incorrectly ran as: Cursor Grok 4.6 High

For AI issues: add Request ID with privacy disabled

c7025b0e-10fc-4f16-8e74-7a2a69bcf981

Additional Information

  • Reproduced in Multitask / parallel agent session
  • Subagent model selection does not respect the parent picker
  • Impact: unexpected billing/usage drain because Grok 4.6 High is billed instead of Composer 2.5
  • Branch context in screenshot: feat/seller-experience
  • Environment shown: This Mac
  • Happy to provide more request IDs if useful
  • CC @deanrie

Does this stop you from using Cursor

Sometimes - I can sometimes use Cursor

5

Hey, thanks for the detailed report and for including the Request ID, that really helped.

You’re reading it right: the main chat was running on Composer 2.5, but the spawned subagent started on Cursor Grok 4.6 High. From your Request ID, it looks like the agent itself picked the model for the subagent when handing off the task, not your picker or settings. This is a known issue we’re tracking, and I’ve attached your report with the Request ID to it.

As a temporary workaround, add an explicit instruction in your prompt or in User Rules, something like: “subagents must always run on the same model I have selected”. The agent is more likely to follow a direct instruction when choosing a subagent model, so this reduces how often it switches.

I can’t share a timeline yet, but I’ll reply here as soon as there’s an update. If you catch more cases, feel free to send the Request ID, it won’t hurt.