Compaction fails with - Unknown parameter: 'prompt_cache_retention'.

What version of Codex CLI is running?

0.120.0

What subscription do you have?

ChatGPT Pro

Which model were you using?

GPT-5.4

What platform is your computer?

Linux 5.15.158-2-pve x86_64 unknown

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

Terminal.app

What issue are you seeing?

When I try /compact or it auto-compacts it fails with this:

■ Error running remote compact task: {
"error": {
"message": "Unknown parameter: 'prompt_cache_retention'.",
"type": "invalid_request_error",
"param": "prompt_cache_retention",
"code": "unknown_parameter"
}
}

What steps can reproduce the bug?

/compact

What is the expected behavior?

IT compacts

Additional information

_No response_