Subnet DemoSubnet is in use and cannot be updated - azure

Question

I have created a DemoSubnet and an ElasticIP, then I am trying to deploy a ARM template which has a Virtual machine which is trying to attach with that existing elastic IP. The template works fine initially, and after some time its failing due to below error
"At least one resource deployment operation failed. Please list
deployment operations for details"
Here is the detailed error message from the arm template deployment:
Details=[{"code":"BadRequest","message":"{\r\n \"error\": {\r\n
\"code\": \"InUseSubnetCannotBeUpdated\",\r\n \"message\": \"Subnet
DemoSubnet is in use and cannot be updated.\",\r\n \"details\":
[]\r\n }\r\n}"}]
ARM Temaplate
{
"$schema": "https://schema.management.azure.com/schemas/2015-01-01/deploymentTemplate.json#",
"contentVersion": "1.0.0.0",
"parameters": {
"addressPrefixes": {
"defaultValue": [
"10.0.0.0/16"
],
"type": "Array",
"metadata": {
"description": "Address prefix of the virtual network"
}
},
"location": {
"defaultValue": "[resourceGroup().location]",
"type": "String",
"metadata": {
"description": "Location for all resources."
}
},
"publicIpNewOrExisting": {
"defaultValue": "existing",
"type": "String",
"metadata": {
"description": "Determines whether or not a new public ip should be provisioned."
}
},
"publicIpResourceGroupName": {
"defaultValue": "[resourceGroup().name]",
"type": "String",
"metadata": {
"description": "Name of the resource group for the public ip address"
}
},
"storageAccountResourceGroupName": {
"defaultValue": "[resourceGroup().name]",
"type": "String",
"metadata": {
"description": "Name of the resource group for the existing storage account"
}
},
"storageNewOrExisting": {
"defaultValue": "existing",
"type": "String",
"metadata": {
"description": "Determines whether or not a new storage account should be provisioned."
}
},
"subnetPrefix": {
"defaultValue": "10.0.0.0/24",
"type": "String",
"metadata": {
"description": "Subnet prefix of the virtual network"
}
},
"virtualNetworkNewOrExisting": {
"defaultValue": "existing",
"type": "String",
"metadata": {
"description": "Determines whether or not a new virtual network should be provisioned."
}
},
"virtualNetworkResourceGroupName": {
"defaultValue": "[resourceGroup().name]",
"type": "String",
"metadata": {
"description": "Name of the resource group for the existing virtual network"
}
}
},
"resources": [
{
"type": "Microsoft.Compute/virtualMachines",
"apiVersion": "2018-10-01",
"name": "SampleVM",
"location": "[parameters('location')]",
"dependsOn": [
"[resourceId(parameters('storageAccountResourceGroupName'),'Microsoft.Storage/storageAccounts/', 'SampleStorageAccnt')]",
"[resourceId('Microsoft.Network/networkInterfaces/', 'SampleNIF')]"
],
"properties": {
"diagnosticsProfile": {
"bootDiagnostics": {
"enabled": true,
"storageUri": "[reference(resourceId(parameters('storageAccountResourceGroupName'),'Microsoft.Storage/storageAccounts/', 'SampleStorageAccnt')).primaryEndpoints.blob]"
}
},
"hardwareProfile": {
"vmSize": "Standard_A2"
},
"networkProfile": {
"networkInterfaces": [
{
"id": "[resourceId('Microsoft.Network/networkInterfaces','SampleNIF')]"
}
]
},
"osProfile": {
"adminPassword": "rajnikaur#253",
"adminUsername": "adminuser",
"computerName": "SampleVM"
},
"storageProfile": {
"dataDisks": [
{
"createOption": "Empty",
"diskSizeGB": 1023,
"lun": 0
}
],
"imageReference": {
"offer": "WindowsServer",
"publisher": "MicrosoftWindowsServer",
"sku": "2016-Datacenter",
"version": "latest"
},
"osDisk": {
"createOption": "FromImage"
}
}
}
},
{
"type": "Microsoft.Storage/storageAccounts",
"apiVersion": "2019-04-01",
"name": "SampleStorageAccnt",
"location": "[parameters('location')]",
"kind": "Storage",
"condition": "[equals(parameters('storageNewOrExisting'), 'existing')]"
},
{
"type": "Microsoft.Network/networkInterfaces",
"apiVersion": "2019-09-01",
"name": "SampleNIF",
"location": "[parameters('location')]",
"dependsOn": [
"[resourceId(parameters('virtualNetworkResourceGroupName'),'Microsoft.Network/virtualNetworks/', 'sampleVnet')]",
"[resourceId(parameters('publicIpResourceGroupName'),'Microsoft.Network/publicIPAddresses', 'DemoEIP')]"
],
"properties": {
"ipConfigurations": [
{
"name": "ipconfig",
"properties": {
"privateIPAllocationMethod": "Dynamic",
"publicIPAddress": {
"id": "[resourceId(parameters('publicIpResourceGroupName'),'Microsoft.Network/publicIPAddresses', 'DemoEIP')]"
},
"subnet": {
"id": "[resourceId(parameters('virtualNetworkResourceGroupName'),'Microsoft.Network/virtualNetworks/subnets', 'sampleVnet', 'DemoSubnet')]"
}
}
}
]
}
},
{
"type": "Microsoft.Network/publicIPAddresses",
"apiVersion": "2017-09-01",
"name": "DemoEIP",
"location": "[parameters('location')]",
"properties": {
"publicIPAllocationMethod": "Static"
},
"condition": "[equals(parameters('publicIpNewOrExisting'), 'existing')]"
},
{
"type": "Microsoft.Network/virtualNetworks",
"apiVersion": "2017-09-01",
"name": "sampleVnet",
"location": "[parameters('location')]",
"properties": {
"addressSpace": {
"addressPrefixes": "[parameters('addressPrefixes')]"
},
"subnets": [
{
"name": "DemoSubnet",
"properties": {
"addressPrefix": "[parameters('subnetPrefix')]"
}
}
]
},
"condition": "[equals(parameters('virtualNetworkNewOrExisting'), 'existing')]"
}
]
}