Our SAML2 settings are mirrored to those in the documentation, so we are unsure what the issue is. When attempting to navigate to https://dashboard.domain.com/saml2/acs it states:
You will want to check the logs on the server for a more detailed error message. In Azure, you can use the Kudu portal to view logs. Logs are also written to log stream if you enable it.
The logs show:
[ERR] An unhandled exception has occurred while executing the request.
System.Configuration.ConfigurationErrorsException: Unexpected entity id “https://sts.windows.net/..../” found when loading metadata for “https://sts.windows.net/…”.