Microsoft.DeviceUpdate RP stuck in 'Registering' state — all instance creates fail with InternalServerError

We are unable to create any new Microsoft.DeviceUpdate/accounts/instances resources in our subscription. Every attempt — via Bicep, ARM, Azure CLI, and the Azure Portal — fails with the same opaque error:

{

"code": "InternalServerError",

"message": "Job failed due to an internal error."

}

Activity log shows no further detail beyond ResourceOperationFailure → InternalServerError.

The Microsoft.DeviceUpdate resource provider in this subscription has been stuck in Registering state for 24+ hours.

registrationState : Registering

registrationPolicy : RegistrationRequired

namespace : Microsoft.DeviceUpdate

providerAuthorizationConsentState: (empty)

Forcing re-registration (az provider register -n Microsoft.DeviceUpdate --wait) does not complete and the RP never returns to Registered.

Environment:

• Subscription: [REDACTED]
• Tenant: Microsoft TME [REDACTED]
• Region: West US 2 (account location)
• API version tried: Both 2022-10-01 and 2023-07-01

What we've verified:

• Existing ADU resources in the same subscription (created Oct 2025) work normally — only new instance creates fail.
• The IoT Hub being linked is healthy (provisioningState: Succeeded, state: Active) and has the deviceupdateservice shared access policy.
• The ADU first-party service principal in this tenant (objectId [REDACTED], appId [REDACTED], displayName Azure Device Update) has been granted IoT Hub Data Contributor on the linked hub.
• The parent Microsoft.DeviceUpdate/accounts resource provisions successfully and shows provisioningState: Succeeded — only the child accounts/instances resource fails.
• Resource locks, policies, and quotas are not blocking the operation.
• All ADU subscription feature flags are NotRegistered, but they were also NotRegistered when our existing working instances were created, so this should not be the cause.

Repro:

1. In subscription above, create any Microsoft.DeviceUpdate/accounts/instances resource (any name, any RG, link to any healthy IoT Hub).
2. Resource transitions to provisioningState: Failed within 30s with InternalServerError.

What we need:

• Confirmation whether Microsoft.DeviceUpdate RP being stuck in Registering is a known issue or service-side problem.
• Guidance on how to force the RP back to a healthy Registered state, or whether this requires PG intervention.Forcing re-registration (az provider register -n Microsoft.DeviceUpdate --wait) does not complete and the RP never returns to Registered. Environment:

      - **Subscription:** [REDACTED]
    
    
      - **Tenant:** Microsoft TME [REDACTED]
    
      
         - **Region:** West US 2 (account location)
    
         
            - **API version tried:** Both `2022-10-01` and `2023-07-01`
  

  What we've verified:
  • Existing ADU resources in the same subscription (created Oct 2025) work normally — only new instance creates fail.
    • The IoT Hub being linked is healthy (provisioningState: Succeeded, state: Active) and has the deviceupdateservice shared access policy.
      • The ADU first-party service principal in this tenant (objectId [REDACTED] , appId[REDACTED], displayName Azure Device Update) has been granted IoT Hub Data Contributor on the linked hub.

                              - The parent `Microsoft.DeviceUpdate/accounts` resource provisions successfully and shows `provisioningState: Succeeded` — only the child `accounts/instances` resource fails.
                
                  
                     - Resource locks, policies, and quotas are not blocking the operation.
                
                     
                        - All ADU subscription feature flags are `NotRegistered`, but they were also `NotRegistered` when our existing working instances were created, so this should not be the cause.
                
                        
                  **Repro:**
        

        1. In subscription above, create any Microsoft.DeviceUpdate/accounts/instances resource (any name, any RG, link to any healthy IoT Hub).
        2. Resource transitions to provisioningState: Failed within 30s with InternalServerError.
    What we need:
  • Confirmation whether Microsoft.DeviceUpdate RP being stuck in Registering is a known issue or service-side problem.
  • Guidance on how to force the RP back to a healthy Registered state, or whether this requires PG intervention.