Slow connections and 503 errors

What version of Codex CLI is running?

codex-cli 0.118.0

What subscription do you have?

pro

Which model were you using?

gpt-5.3-codex-spark xhigh

What platform is your computer?

Darwin 25.3.0 arm64 arm

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

Iterm2

What issue are you seeing?

503 errors and slow interaction with the spark models.

What steps can reproduce the bug?

Uploaded thread: 019d6af9-d7ae-7651-9004-794a6edb704b

What is the expected behavior?

_No response_

Additional information

└ Unexpected status 503 Service Unavailable: upstream connect error or disconnect/reset before headers. reset reason: connection termination, url:
wss://chatgpt.com/backend-api/codex/responses, cf-ray: 9e8e08673db4979c-ADL