Unnecessary request to Azure B2C for 2nd application login

Hey all,


  • Applications A and B (Both .Net Framework)
  • Auth0 (Actually a double setup with Product Group Tenant and Master Tenant, but that is probably not relevant for this setup)
  • External IDP > Azure B2C (SAML Connection)

We are experiencing a problem when logging in with Auth0. When Im logged in with App A, and use Azure B2C for authentication everything is going great. User is successfully logged in into application A and also in Azure.
Problem starts when logging in with App B. Whenever a user does that, a call to Auth0 will be done to authenticate, but also to Azure B2C.
Why is the call to Azure B2C made, when I have already logged into Auth0? The same call in IdentityServer does not progress beyond Identityserver itself, which is as expected?

What can trigger this behavior?

  • Requested scope is similar, although App B requests less.
  • Token type in request is more in App B. App A requests idtoken and code, whilst B requests also the accesstoken right away.
  • Endpoints are the same
  • Connection is the same (SAML)