Set-AzVirtualNetwork does not attach Nat Gateway to a subnet in Azure

I followed the exact Microsoft Documentation to attach a Nat Gateway to a subnet however, it does not set it as expected.

$pip = New-AzPublicIpAddress -Name "pip" -ResourceGroupName "natgateway_test" -Location "eastus2" -Sku "Standard" -IdleTimeoutInMinutes 4 -AllocationMethod "static"

$natGateway = New-AzNatGateway -ResourceGroupName "natgateway_test" -Name "nat_gateway" -IdleTimeoutInMinutes 4 -Sku "Standard" -Location "eastus2" -PublicIpAddress $pip

$frontendSubnet = New-AzVirtualNetworkSubnetConfig -Name frontendSubnet -AddressPrefix "10.0.1.0/24"

$virtualNetwork = New-AzVirtualNetwork -Name MyVirtualNetwork -ResourceGroupName TestResourceGroup -Location centralus -AddressPrefix "10.0.0.0/16" -Subnet $frontendSubnet

Set-AzVirtualNetworkSubnetConfig -Name frontendSubnet -VirtualNetwork $virtualNetwork -InputObject $natGateway

$virtualNetwork | Set-AzVirtualNetwork

Link To Microsoft Documentation

is there a workaround for this?. how can I get my existing subnet attached to my Nat Gateway successfully?.

In the command Set-AzVirtualNetworkSubnetConfig -Name frontendSubnet -VirtualNetwork $virtualNetwork -InputObject $natGateway, the -InputObject parameter expects a subnet configuration object, not a NAT Gateway object. Passing a NAT Gateway object does not update the subnet’s NatGateway property and will not attach the NAT Gateway to the subnet.

I followed the approach below and was able to attach the NAT Gateway to the subnet.

# Create Public IP
$pip = New-AzPublicIpAddress -Name "<Public ip name>" `
    -ResourceGroupName "<Resource group name>" `
    -Location "<Region name>" `
    -Sku "Standard" `
    -IdleTimeoutInMinutes 4 `
    -AllocationMethod "Static"

# Create NAT Gateway
$natGateway = New-AzNatGateway -ResourceGroupName "<Resource group name>" `
    -Name "nat_gateway" `
    -IdleTimeoutInMinutes 4 `
    -Sku "Standard" `
    -Location "<Region name>" `
    -PublicIpAddress $pip

# Get the existing VNet and Subnet
$virtualNetwork = Get-AzVirtualNetwork -Name "<VNET name>" -ResourceGroupName "<Resource group name>"
$subnet = Get-AzVirtualNetworkSubnetConfig -Name "<Subnet name>" -VirtualNetwork $virtualNetwork

# Attach NAT Gateway to the subnet
$subnet.NatGateway = $natGateway

# Replace the subnet in the VNet's subnet collection
for ($i = 0; $i -lt $virtualNetwork.Subnets.Count; $i++) {
    if ($virtualNetwork.Subnets[$i].Name -eq "<Name of sunet>") {
        $virtualNetwork.Subnets[$i] = $subnet
    }
}

# Push the updated VNet to Azure
Set-AzVirtualNetwork -VirtualNetwork $virtualNetwork

# Output the NAT Gateway ID attached to the subnet
(Get-AzVirtualNetworkSubnetConfig -Name "<Name of sunet>" -VirtualNetwork $virtualNetwork).NatGateway.Id

Output: