[BUG] Login redirects to account creation for existing account with active Max Suscription

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Since 6 Oct 2026 I cannot log in to my existing account on claude.ai (web) or Claude Desktop (macOS). Email verification succeeds, but I am then redirected to new-account registration instead of my existing account.

The iOS app with the same email still works and shows the active Max plan.

Tried: several browsers, reinstalling the desktop app, with and without VPN. Same result.

Support case 215476261169977: subscription confirmed active on 6 Oct; no technical response since.

Same pattern as #36797, #57842, #74236. Request: backend fix of the email-to-account mapping.

What Should Happen?

I should be logged into my existing account.

Error Messages/Logs

Steps to Reproduce

1.⁠ ⁠Go to claude.ai or open Claude Desktop on macOS.
2.⁠ ⁠Sign in with the account email and verify it.
3.⁠ ⁠Redirected to account creation instead of the existing account.

Claude Model

_No response_

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

n/a

Platform

Other

Operating System

macOS

Terminal/Shell

Other

Additional Information

_No response_