Grok 4.5 is only called as "Fast"

Support Bug Reports
,
1

Describe the Bug

Kimi K3, acting as the leader throughout the session, invokes the preconfigured subagent model: grok-4.5[effort=high,fast=false] exclusively in fast mode.

Steps to Reproduce

Just using broken again Cursor?

Screenshots / Screen Recordings

2026-08-05_14-44-22.png
2026-08-05_14-44-22.png556×1259 11.7 KB

Operating System

Windows 10/11

Version Information

Version: 3.15.1 (system setup)
VS Code Extension API: 1.128.0
Commit: 41c5e281845de0ce890a8053a3874064bfbdb8b0
Date: 2026-08-04T06:41:23.990Z
Layout: IDE
Build Type: Stable
Release Track: Nightly
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: Windows_NT x64 10.0.22631

For AI issues: which model did you use?

Kimi-K3-Max, Grok-4.5-High

For AI issues: add Request ID with privacy disabled

938f31c1-6ef8-4326-9f34-90156e61815e Privacy On

Additional Information

See also:

Does this stop you from using Cursor

Sometimes - I can sometimes use Cursor

5

Hey @Artemonim
Same Fast-variant behavior you flagged before - it’s an issue we’re tracking, not something in your config.

Workaround that holds today: open the main model picker, select Grok 4.5, set your effort (High), and switch Fast off once. That saved preference is what the subagent falls back to, so it’ll stay non-Fast. Heads up: it applies to Grok 4.5 everywhere (including your parent chat) and saves a single effort level.

We’ve addressed the fast=false opt-out being dropped, and it’s rolling into builds - I’ll post here once it’s in a Nightly you can grab.

6

I thought it might have an effect, but I wasn’t sure. Thanks for the feedback!