I have installed the new Xcode 26.5 release version (and I am on macOS 26.5). It works now! Maybe someone can confirm.

I filed Feedback a couple of days ago: FB22732574

Hey Albert, thanks for your competent reply. Yes, Xcode release candidate 26.5 (17F42). I have deleted the cache. I have also deleted codex* and chatgpt* (empty) from the system keychain. No VPN connection. The problem persists. I have now switched Xcode over to use "Authenticate with configuration file". It does that, but I am unsure whether the configuration file works, and I don't really know how to check. The codex* entries in keychain are back since I logged in on the Codex app. Kind regards

I have filed Feedback with Apple FB13769072