Artifact Signing identity validation fails after successful Face Check with "Unexpected session payload"

I am trying to complete Public Trust identity validation for Azure Artifact Signing.

The identity verification process proceeds normally until the Microsoft Authenticator Verified ID step.

I scan the QR code using Microsoft Authenticator on iOS and complete the Face Check successfully. However, after the Face Check succeeds, Authenticator displays a technical error and the identity validation cannot be completed.

The Microsoft Authenticator diagnostic log shows:

FaceCheckStatus=success

PostPresentationResponseOperation:

HTTP status code: 500

isSuccessful: false

retryable: false

The error hierarchy is:

internalServerError → claimValidationError → facecheckSessionFailure

with the message:

"Unexpected session payload"

After the error occurs, the identity verification URL can no longer be used. Opening it again displays "No Access" / "This link has been used already."

The Artifact Signing identity validation subsequently changes to "Validation Failed."

I have already retried the Artifact Signing identity validation process, but the problem occurred during the Microsoft Verified ID / Face Check submission process.

Since the Face Check itself reports success and the subsequent presentation response returns HTTP 500, this appears to be a server-side or session-processing issue.

Could a Microsoft moderator please help investigate this issue or escalate it to the Artifact Signing / Verified ID team?

I have the complete Microsoft Authenticator diagnostic log, including the Request ID, Flow ID, correlation vector, and timestamp, and can provide these privately if required.