Azure B2C authorize loop in sub-application

GccDev 1 Reputation point


I'm currently using Azure B2C to authenticate a series of .NET 6 server-side Blazor apps and Web APIs. In IIS, the apps are setup as follows:
If a user logs into and then navigates to, /admin gets caught in an infinite authorize loop with Azure B2C. Then, if you browse back to and logout, you can navigate back to /admin and currently be signed in.

However, if you log into /admin first and navigate to, you will be successfully logged in. Then, if you navigate back to /admin, you get stuck in a auth loop again.

I have verified that the only difference between the 2 access tokens is the audience and the timestamps issued (of course). In B2C, I have both web applications set to accept access tokens from any app authorizing with the B2C domain.

I have also tried setting up my cookies with settings from here: Cookie Sharing.

Logging into then logging into /admin causes the loop. Then, if I log out of and navigate back /admin, the loop stops and I'm authenticated.

Dev tools show zero errors and from what I can tell in code, it appears like I am authenticated.

Any help/guidance I can get would be greatly appreciated.

A free and open-source web framework that enables developers to create web apps using C# and HTML being developed by Microsoft.
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Microsoft Entra External ID
Microsoft Entra External ID
A modern identity solution for securing access to customer, citizen and partner-facing apps and services. It is the converged platform of Azure AD External Identities B2B and B2C. Replaces Azure Active Directory External Identities.
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  1. Michael Washington 911 Reputation points MVP

    "" and "" need to each have a Redirect URIs. It appears to me that "" does not a a redirect URI set.

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