ResourceDeploymentFailure when creating a HostPool for Azure Virtual Desktop

When I try to create a Azure Virtual Desktop I get the following error:

{
  "code": "DeploymentFailed",
  "target": "/subscriptions/a-b-c-d-e/resourceGroups/rg-avd-wcus/providers/Microsoft.Resources/deployments/HostPool-x-y-z-æ-ø-deployment",
  "message": "At least one resource deployment operation failed. Please list deployment operations for details. Please see https://aka.ms/arm-deployment-operations for usage details.",
  "details": [
    {
      "code": "ResourceDeploymentFailure",
      "target": "/subscriptions/a-b-c-d-e/resourceGroups/rg-avd-wcus/providers/Microsoft.DesktopVirtualization/hostpools/hp-avd-wcus/sessionHostConfigurations/default",
      "message": "The resource write operation failed to complete successfully, because it reached terminal provisioning state 'Failed'."
    }
  ]
}

Anyone know what it is or how I can fix it?

Subscription

Subscription  Microsoft.DesktopVirtualization = Registered

Resource group

Resource group Region = (US) West Central US 

Virtual network

Region: (US) West Central US 

Key vault

Region: (US) West Central US 

Pricing tier: Standard

Access control (IAM): Gave myself Key Vault Administrator

Key Vault → Objects → Secrets → Generate/Import 

Name: avd-admin-username

Name: avd-admin-password 

AVD Host Pool

Location: (US) West Central US

Validation environment: No

Preferred app group type: Dektop

Host pool type: Pooled

Create Session Host Configuration: Yes

Load balancing algorithm: Depth-first

Max session limit: 5

Session hosts

Number of session hosts: 1

Name prefix: vm-avdwcus

Location: (US) West Central US

Availability options: No infrastructure required

Secure type: Trusted launch virtual machine

Image: Windows 11 Enterprise mulit-session, Version 25H2

Size: Standard D2as v5

Number of VMs: 1

OS disk type; Standard HDD

OS disk size: Default size (128 GB)

Virtual network: vn-avd-network-wcus

Public inbound port: No

Domain to join: Microsoft Entra ID

Entroll VM with Intune: Yes