https://learn.microsoft.com/en-us/troubleshoot/azure/active-directory/error-code-aadsts75011-auth-method-mismatch#cause
The SSO works from Chrome and doesn't work from Edge.Can someone dumb down the cause for me? Does just trying from a different browser change the Authentication context? Or is this a different context that has changed? What are the different types of contexts possible?
Best Answer
We had the same issue. We found you could open it from Edge if you used a new Private window. Alternatively, log out of all your SSO completely and then try logging into the application. When prompted, don't choose your existing profile, instead click the sign in with another account one.
Here was the hint from the article you linked to: "However, the user has already authenticated prior to access the application and the AuthnContext (authentication method) used for that previous authentication is different from the one being requested."