Where does the bug appear (feature/product)?
Cursor IDE
Describe the Bug
In Cursor 3.1.17 Agents/Glass UI one can only control MAX mode but not thinking levels nor speed (fast mode). This has a new UI to select it in the agent chat box rather than in settings, but this UI does not appear in Agents/Glass UI and thus users cannot select the fast models or different levels of thinking at all.
This specifically breaks my Opus 4.6 FAST usage which is my primary model.
Steps to Reproduce
Upgrade to 3.1.17, try to configure models.
Operating System
MacOS
Version Information
Version: 3.1.17
VSCode Version: 1.105.1
Commit: fce1e9ab7844f9ea35793da01e634aa7e50bce90
Date: 2026-04-19T19:33:58.189Z
Layout: glass
Build Type: Stable
Release Track: Default
Electron: 39.8.1
Chromium: 142.0.7444.265
Node.js: 22.22.1
V8: 14.2.231.22-electron.0
OS: Darwin arm64 25.3.0
Does this stop you from using Cursor
Sometimes - I can sometimes use Cursor