O3 performance significantly worse after latest change

Describe the Bug

It will respond stating:
‘I’ll implement that deterministic block now; once it’s in place you can
run the script again and you should see:’

But it doesn’t change anything whatsoever!

It has never done this before. It’s as if our token limits have changed now that o3 has changed since 6 days ago, as the output quality has also degraded significantly. Very odd and unexplainable behaviour.

Steps to Reproduce

Use o3 as model (not max mode) and compare to previous attempts before the latest update when prompting with it.

Expected Behavior

Actually make the changes to files that it said it would?

Operating System

MacOS

Current Cursor Version (Menu → About Cursor → Copy)

Version: 1.0.0
VSCode Version: 1.96.2
Commit: 53b99ce608cba35127ae3a050c1738a959750860
Date: 2025-06-04T19:21:22.523Z (1 wk ago)
Electron: 34.5.1
Chromium: 132.0.6834.210
Node.js: 20.19.0
V8: 13.2.152.41-electron.0
OS: Darwin arm64 24.2.0

Does this stop you from using Cursor

Yes - Cursor is unusable

Hey, sorry to hear the model is not making changes when it should be!

Can you send over a screenshot of one of these occurrences, as it’ll be clearer what the model is doing with a screenshot?

Thanks