Install cluster with user-defined data disk configured on compute in Azure Stack Hub, compute machines failed to be provisioned.

install-config.yaml, etcd data disk configured on controlPlane, user-defined data disk configured on compute
===========
compute:
- architecture: amd64
  hyperthreading: Enabled
  name: worker
  platform:
    azure:
      dataDisks:
      - cachingType: ReadWrite
        diskSizeGB: 128
        lun: 1
        nameSuffix: vardisk
  diskSetup:
  - type: user-defined
    userDefined:
      platformDiskID: vardisk
      mountPath: /var
  replicas: 3
controlPlane:
  architecture: amd64
  hyperthreading: Enabled
  name: master
  platform:
    azure:
      dataDisks:
      - cachingType: ReadOnly
        diskSizeGB: 512
        lun: 10
        nameSuffix: etcddisk
  diskSetup:
  - type: etcd
    etcd:
      platformDiskID: etcddisk
  replicas: 3
<......>
platform:
  azure:
    region: mtcazs
    baseDomainResourceGroupName: os4-common
    cloudName: AzureStackCloud
    clusterOSImage: https://vhdsaqe.blob.mtcazs.wwtatc.com/vhd/rhcos-9.6.20250523-0-azurestack.x86_64.vhd
    armEndpoint: https://management.mtcazs.wwtatc.com
   
ControlPlane machines provisioned successfully, installer failed at stage of waiting for cluster completed because all worker machines provisioned failed. I see that they were creating, then timeout and moved into "Stopped" status finally.

On portal, data disk was not created, only os disk was created for each compute machine.
$ az resource list -g jima2401-qkfm5-rg -otable | grep worker
jima2401-qkfm5-worker-mtcazs-mdp2b_OSDisk        JIMA2401-QKFM5-RG  mtcazs      Microsoft.Compute/disks
jima2401-qkfm5-worker-mtcazs-pjv9d_OSDisk        JIMA2401-QKFM5-RG  mtcazs      Microsoft.Compute/disks
jima2401-qkfm5-worker-mtcazs-w7btg_OSDisk        JIMA2401-QKFM5-RG  mtcazs      Microsoft.Compute/disks
jima2401-qkfm5-worker-mtcazs-mdp2b               jima2401-qkfm5-rg  mtcazs      Microsoft.Compute/virtualMachines
jima2401-qkfm5-worker-mtcazs-pjv9d               jima2401-qkfm5-rg  mtcazs      Microsoft.Compute/virtualMachines
jima2401-qkfm5-worker-mtcazs-w7btg               jima2401-qkfm5-rg  mtcazs      Microsoft.Compute/virtualMachines
jima2401-qkfm5-worker-mtcazs-mdp2b-nic           jima2401-qkfm5-rg  mtcazs      Microsoft.Network/networkInterfaces
jima2401-qkfm5-worker-mtcazs-pjv9d-nic           jima2401-qkfm5-rg  mtcazs      Microsoft.Network/networkInterfaces
jima2401-qkfm5-worker-mtcazs-w7btg-nic           jima2401-qkfm5-rg  mtcazs      Microsoft.Network/networkInterfaces
 

Below is machineset spec:
$ oc get machineset.m -n openshift-machine-api -ojson | jq -r ".items[].spec.template.spec.providerSpec.value.dataDisks"
[
  {
    "cachingType": "ReadWrite",
    "deletionPolicy": "Delete",
    "diskSizeGB": 128,
    "lun": 1,
    "managedDisk": {
      "storageAccountType": ""
    },
    "nameSuffix": "vardisk"
  }
]

    image built with PR https://github.com/openshift/installer/pull/9706

    Always

    1. Configure etcd data disk for controlPlane, and user-defined data disk for compute in install-config.yaml file
    2. Create cluster on Azure Stack Hub
    3.
    

    Installation failed, compute machines failed to be provisioned

    Installation succeeded