FlexConsumption Deployment AzureDevops Error

[chrisgray94]

I have deployed Flex Consumption plan and app via Bicep. I am using the AzureWebJobsStorage__accountname app setting and system assigned identity which I have given Storage Blob Data Contributor access to the storage account. I am using az functionapp deployment source config-zip CLI task in AzurePipelines yml file to deploy the code to the container I am using inside the deployment settings. However, the task always fails with "ERROR: Failed to fetch host key to check for function app status". Any ideas? I do have other app settings for things like service bus which I have given access to with the identity as above. I am using vnet integration and the subnet also has access to the storage account. Please find the bicep template below. I apologise if I've raised this in the wrong repository. I am using dotnet-isolated runtime and version 8.0

resource flexApp 'Microsoft.Web/sites@2023-12-01' = {
name: appName
kind: 'functionapp,linux'
location: location
tags: {
app: app
environment: environment
}
properties: {
httpsOnly: true
serverFarmId: flexPlan.id
virtualNetworkSubnetId: subnetId
siteConfig: {
appSettings: appSettings
minTlsVersion: '1.2'
http20Enabled: true
publicNetworkAccess: 'Enabled'
cors: {
allowedOrigins: [
corsUrl
]
}
}
functionAppConfig: {
deployment: {
storage: {
type: 'blobContainer'
value: 'https://${storageAccountName}.blob.${az.environment().suffixes.storage}/${storageContainerName}'
authentication: {
type: 'SystemAssignedIdentity'
}
}
}
scaleAndConcurrency: {
maximumInstanceCount: numOfInstances
instanceMemoryMB: 2048
}
runtime: {
name: runtimeName
version: netFrameworkVersion
}
}
}
identity: {
type: 'SystemAssigned'
}
}

In the portal I also see this