Resolved
GPT-5.5 is now available to all paid users in Codex. If you continue to see access issues, please update to the latest Codex version. We’ll share another update if needed.
Investigating
We’re investigating elevated errors affecting Codex gpt-5.5 usage. Some users may see intermittent “not found” errors when starting or updating requests. We’re working to mitigate the issue and will share another update soon.