Artifact Signing organization verification: You need permission with matching email and required Azure roles

We are completing Public organization identity validation in Azure Artifact Signing. The request was last observed as In Progress, and we received an Action Required email asking the representative to complete verification.

The existing guest identity has Owner at subscription scope and Artifact Signing Identity Verifier on the signing account. The primary email on the validation request exactly matches the signed-in email displayed on the verification page. The Azure resource is accessible with MFA.

However, the representative verification page immediately returns You need permission / noPermission, preventing verification from continuing. It displays the account in the Microsoft consumer tenant, while the Azure signing resource belongs to a different tenant. We do not know whether this explains the failure.

We retried the original verification link in the same browser and in a private session with the same account; both failed. The Microsoft account is GitHub-linked, but whether that is relevant is unknown.

Could Microsoft advise the supported way to investigate or correct the request-to-identity mapping while preserving the existing request and avoiding unnecessary tenant or role changes? The Azure technical-support form requires a paid support plan. Is there an official private channel for validation/account identifiers and diagnostic evidence?

No email address, Azure identifiers, personal verification link, identity documents, or screenshots are included in this public question.