Claude Code bills API instead of Max subscription — OAuth response missing organizationType for specific org

Environment

• macOS, Claude Code CLI + VS Code extension (both reproduce)
• Claude Code version: latest

Symptom

Every session shows · API Usage Billing. After OAuth, ~/.claude.json writes oauthAccount: null and hasAvailableSubscription: false, causing Claude Code to fall through to API billing instead of consuming the Max subscription.

Affected org

6a3344e3-6ad4-44ef-a191-cc40aba0f8a9 (Claude Max 20x — Anthropic support confirmed subscription is active for this org)

Working pre-incident state (from backup ~/.claude.json)

"organizationType": "claude_max",
"organizationRateLimitTier": "default_claude_max_20x"

Current post-OAuth state

"oauthAccount": null,
"hasAvailableSubscription": false

Proof this is server-side

Modified the OAuth URL's orgUUID param to a different org on the same account (7e6c2941-f4cf-42db-b0a1-93f3b9224dd5) — that org's metadata wrote correctly into ~/.claude.json (UUID and name populated). The OAuth flow itself works. The affected org's backend response is specifically missing subscription metadata fields.

Also tested: removed Google SSO requirement from the affected org and retried with email-only login — still returned null. SSO routing is not the cause.

Client-side exhaustively ruled out

• No ANTHROPIC_API_KEY anywhere: env, shell rc, launchctl, settings.json, managed-settings.json, root-owned managed-settings
• Keychain entries (Claude Code-credentials, Claude Code-credentials-ab061586) fully deleted and re-created
• Fresh CLAUDE_CONFIG_DIR tested
• Switched to plain Sonnet 4.6 (ruling out 1M-context tier as cause)
• Both VS Code extension and standalone CLI reproduce identically

Request

Backend investigation into why org 6a3344e3-6ad4-44ef-a191-cc40aba0f8a9 is not returning organizationType / organizationRateLimitTier in its OAuth response. The subscription is confirmed active — the metadata is simply not being returned for this specific org.