Fast mode activates on its own

[kgaspard]

What version of Codex CLI is running?

codex-cli 0.130.0

What subscription do you have?

Business

Which model were you using?

gpt-5.5

What platform is your computer?

Darwin 25.3.0 arm64 arm

What terminal emulator and version are you using (if applicable)?

iTerm2

Codex doctor report

Not working (`error: unexpected argument '--json' found`)

What issue are you seeing?

Codex seems to automatically activate fast mode, despite me neither explicitly (with the slash command) nor implicitly asking for it. I can deactivate it with /fast, and I can see it get deactivated (fast disappears from the bottom of the CLI as expected), but after a few messages it comes back on its own.

What steps can reproduce the bug?

See above

What is the expected behavior?

No response

Additional information

No response

[etraut-openai]

If this happens again, please use /feedback to upload your logs and post the session ID here.

[etraut-openai]

When you disable fast mode using /fast, you should see fast_default_opt_out = true written to your config file. If you open ~/.codex/config.toml, do you see this config key?

[etraut-openai]

I just found a repro of the problem. It required me to use /agent to switch to a subagent thread or /side to switch to a side conversation. When I returned to the main thread, fast mode was reported as on. It was actually off still, but the TUI reported a stale state. Do you remember using /agent or /side?

[kgaspard]

@etraut-openai apologies, I never received the notification for your replies. It seems the issue is closed but on the off chance it's still helpful:

• Re; /feedback, will do
• I used neither /agent nor /side. I frequently use /model to change the model and/or effort.
• Will check the config file if it happens again