Auth0 SSO Session Not Recognize - Request to re-login

Description:

I’m experiencing an SSO issue where users who are already authenticated in our Auth0 application are being prompted to sign in again through Auth0 (not a third-party login) when accessing a federated third-party service. Here’s our setup:

Current Setup:

  • SPA + API architecture using Auth0
  • Auth0 tenant federated with a third-party authorization server
  • We act as the Identity Provider with our Auth0 tenant
  • OAuth/OIDC flow configured with the third-party service

Expected Behavior: Users authenticated in our Auth0 application should seamlessly access the third-party service without any additional authentication prompts.

Actual Behavior:

  1. Users successfully sign into our Auth0 application
  2. When clicking the third-party integration button for the first time in the session, users are redirected to Auth0 login page (our tenant, not third-party)
  3. Users are required to authenticate again through Auth0
  4. After this re-authentication, the integration works perfectly for the remainder of the session
  5. This suggests the SSO session gets established correctly after the initial re-authentication

Key Details:

  • Users are being prompted to authenticate through our Auth0 tenant (correct IdP), not the third-party service
  • The issue occurs on first access to third-party service within a session
  • Once re-authenticated, SSO works seamlessly
  • We haven’t implemented state parameter handling yet

Questions:

  1. Why isn’t the existing Auth0 session being recognized when initiating the federated flow?
  2. Are there specific SSO session settings in Auth0 that need to be configured for federated scenarios?
  3. Could this be related to session timeout settings or Universal Login implementation?
  4. Is there a difference between application session and Auth0 Authorization Server session that could cause this?

Any guidance on troubleshooting Auth0 SSO session recognition issues would be greatly appreciated.

Environment:

  • Auth0 SPA + API
  • Auth0 tenant acting as IdP
  • Third-party OAuth/OIDC authorization server