postLogoutRedirectUri not working when authority url contains a tenant ID

TL;DR

Two confirmed fixes from the thread: 1. Register the post-logout URI in the Azure portal: App Registrations > Authentication > add your logout URL as a redirect URI.

Steps

1. For the post-logout redirect to work, all of MSAL's logout requirements must hold (the maintainer points to the logout docs checklist). Two confirmed fixes from the thread:
2. Register the post-logout URI in the Azure portal: App Registrations > Authentication > add your logout URL as a redirect URI. Users confirmed the redirect started working a few minutes after whitelisting it.
3. Include logout_hint (taken from the login_hint claim) in the logout request. Several users confirmed this fixed the redirect for them.
4. Background from the maintainer: if the signed-in tenant differs from the logout tenant (guest/external users), the service finds no session and refuses to redirect, so also check you are logging out of the same tenant you signed into. If everything above is done and it still fails, raise it through Azure Support so the service teams get looped in.

When to use

You are seeing this: Reported in Microsoft Entra ID: postLogoutRedirectUri not working when authority url contains a tenant ID. Use this skill when you run into "postLogoutRedirectUri not working when authority url contains a tenant ID".

When not to use

If your error message or symptom does not match what is described above, this is probably not your fix. Search for your exact error text instead of forcing this one to fit.

Versions

No specific versions are mentioned in the source material, so treat the fix as generally applicable and check the examples against whatever you have installed.

Why this happens

The original report does not dig into a root cause. It documents the symptom and the fix that resolved it.

In gh:AzureAD/microsoft-authentication-library-for-js#5783 (https://github.com/AzureAD/microsoft-authentication-library-for-js/issues/5783), the reporter ran into this: Reported in Microsoft Entra ID: postLogoutRedirectUri not working when authority url contains a tenant ID. The verified resolution: For the post-logout redirect to work, all of MSAL's logout requirements must hold (the maintainer points to the logout docs checklist). Two confirmed fixes from the thread:

1. Register the post-logout URI in the Azure portal: App Registrations > Authentication > add your logout URL as a redirect URI. Users confirmed the redirect started working a few minutes after whitelisting it.
2. Include logout_hint (taken from the login_hint claim) in the logout request. Several users confirmed this fixed the redirect for them.

Background from the maintainer: if the signed-in tenant differs from the logout tenant (guest/external users), the service finds no session and refuses to redirect, so also check you are logging out of the same tenant you signed into. If everything above is done and it still fails, raise it through Azure Support so the service teams get looped in.