AJCxZ0​ that's interesting and weird.
Yesterday, I could sign in manually by either typing, copy/pasting, or drag-and-drop the email address from 1Password.
Today, I get the same error 409 as you, no matter which of the manual methods I use. And it's the same on both https://auth.openai.com/log-in/ and https://auth.openai.com/log-in.
The original issue still remains for me though. If I re-enable auto-login, 1Password still just "clicks" the phone number button instead of the continue button.
The issue happens in Chrome, Firefox, Edge and on different devices running both Windows 10 and 11. However, Firefox on iOS does not have this issue, so it might only affect Windows devices.
I'm running the latest versions of Windows and the web browsers mentioned above.
The 1Password desktop app is running version 8.10.75 (81075001).
The browser plugin is using version 8.10.72.25 in Firefox and 8.10.72.27 in Chrome.
The message about error 409 is clearly on OpenAI's side, but the auto-login feature using the wrong button to continue on the login page, seem like a 1Password issue. I've never got the error 400 message about the password being too long, so that issue does not apply to my case.