Healthcare Agent Service F0 provisioning fails with BearerFallbackDisabled / BadGateway in Southeast Asia

I am trying to provision a Microsoft Healthcare Agent Service (Microsoft.HealthBot/healthBots) for an internal evaluation using the Free F0 plan in Southeast Asia.

The subscription is Active and my role is Owner. Microsoft.HealthBot is Registered. No bot resource appears in the resource group.

The deployment overview remains Running, but the operation reports BadGateway with this status message (tracking identifiers omitted):

{"status":"Failed","error":{"code":"BearerFallbackDisabled","message":"Server failed to process the request."}}

I refreshed the Azure portal session, canceled the stalled deployment without deleting resources, and redeployed the same single-resource template with the same F0 plan and location. The second deployment shows the same error.

Could a Microsoft engineer clarify whether this indicates a provider-side provisioning/authentication issue or a required subscription configuration? What is the supported remediation without disabling MFA or weakening authentication? Is new F0 provisioning currently available in Southeast Asia?

This is an evaluation only. No patient data, credentials, or account identifiers are included here. Correlation identifiers can be supplied through an approved private support channel if required.