SAML + Microsoft Entra ID - user_creation_failed error on auto-creation

🔍Authentication❌Unsolved☁️Zitadel Cloud❓Question

Hi everyone!

I'm having an issue with SAML integration between Microsoft Entra ID (as IdP) and Zitadel (as SP) using the TypeScript Login UI (v2).
Environment
Cloud
Binding: HTTP-Redirect

Problem
When a new user tries to authenticate via SAML, the auto-creation fails with user_creation_failed error. The flow redirects to:
/ui/v2/login/idp/saml/complete-registration?...&postErrorRedirectUrl=%2Floginname&error=user_creation_failed
Configuration
IDP settings:

Automatic creation: Enabled

Automatic update: Enabled

Account creation allowed (manually): Enabled

Account linking allowed: Enabled

SAML Response from Entra ID
All required attributes are being sent correctly:
NameID: user@domain.com (format: emailAddress)
givenname: Jefferson
surname: Gonçalves Lemos
displayname: Jefferson Gonçalves Lemos
email: user@domain.com
name: user@domain.com