Auto-complete not working with Custom-tagged union data type

[Dylan-Prins]

@discriminator('type')
type virtualNetwork = existingVirtualNetwork | newVirtualNetwork

type existingVirtualNetwork = {
  type: 'existing'
  virtualNetworkId: string
  nextHopIpAddress: string?
}

type newVirtualNetwork = {
  type: 'new'
  customName: string?
  customVirtualNetworkPeeringName: string?
  addressSpace: string[]
  dnsServers: string[]?
  existingVirtulNetworkHubId: string?
  nextHopIpAddress: string?
}

param virtualNetwork = {
  type: 'new'
  addressSpace: [
    '10.10.0.0/16'
  ]
  
}

I expect dat ik kan use complete when filling in the property, but it does not.