We continue to see the error described here support.oneidentity.com/.../error-unable-to-uniquely-identify-the-user-using-provided-claims-federation-authentication-with-azure-ad
Our on-prem UPN and AzureAD UPN are different, so we are using the feature in AzureAD to provide the on-prem UPN in the claim
The ARS Config
The AzureAD config
