title: Azure AD App got the wrong user to authenticate
body: <p>I have two azure tenants (Tenant A and Tenant B).</p>
  
  <p>I have one registered app (App001) in tenant B with "Supported account types" set to "My organization only".</p>
  
  <p>Here are steps to replicate the issue:</p>
  
  <ol>
  <li>Log into Tenant A's portal (portal.azure.com) with account A001</li>
  <li>Open new tab and try to log into app (App001). It doesn't prompt me to enter account B001 at all. It logs in with account A001 and get this error:
  AADSTS90072: User account '{EmailHidden}' from identity provider '{A001's email domain}' does not exist in tenant '{Tenant A}' and cannot access the application 'xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx'({App001's name}) in that tenant. The account needs to be added as an external user in the tenant first. Sign out and sign in again with a different Azure Active Directory user account</li>
  </ol>
  
  <p>Getting this error is expected because the app's setting does not allow different tenant/directory's user to authenticate.</p>
  
  <p>The question/problem is why it did not prompt me to enter accounts for Tenant B?
  Any place I should take a look at the settings?</p>