Cannot spin up using only internal IP

[nekodojo]

I'm trying to spin up an instance using only internal IP (no external allowed). I get the message

Specified external IP address is invalid or does not exist.
IP address requested: false

Yes, I did configure external IP to be disabled. From my laptop, we already have VPN set up to be able to access the private ranges directly. But, it looks like it is not even getting to the spin up stage, only the info block followed by this message.

I have retried with both google.use_private_ip = "true" and google.use_private_ip = "false" - in both cases I am keeping google.external_ip = "false". Both cases give the same error.

Full config with some of my details removed

Vagrant.configure("2") do |config|
  config.vm.box = "google/gce"

  ## this provider details are on https://github.com/mitchellh/vagrant-google 
  config.vm.provider :google do |google, override|
    google.google_project_id  = "xxxproject"
    # google.image_project_id   = 'debian-cloud'
    # google.image_family       = 'debian-11'
    google.image_project_id   = 'ubuntu-os-cloud'
    google.image_family       = 'ubuntu-2004-lts'
    google.machine_type       = "e2-standard-2"
    google.disk_type          = "pd-standard"
    google.network            = "xxxnetwork"
    google.subnetwork         = "xxxsubnetwork"
    google.external_ip        = "false"  # This didn't work for me
    google.use_private_ip     = "true"  # tried both true and false
    google.auto_restart       = "false"
    google.zone               = "us-central1-f"
    
    override.ssh.username = "myuser"
    override.ssh.private_key_path = "~/.ssh/id_rsa"
  end

    config.vm.box_check_update = false
    
    # # Sample shell startup for all node types
    # config.vm.provision :shell, :path => "linux/ubuntu/20.04/prerequisites.sh"
    
    # Plan automatic shutdown of machine to prevent unwanted costs
    config.vm.provision "auto-shutdown", type: "shell", run: "always",
      inline: "shutdown -P +120" # = 60 minutes * 2 hours
    
    config.vm.define "gconnor-jump-stage" do |mybox|
        mybox.vm.hostname = "gconnor-jump-stage"
        
        # # Sample shell startup for specific node type
        # config.vm.provision :shell, :path => "linux/ubuntu/20.04/prerequisites.sh"
        
        # # Sample ansible start provisioning
        # mybox.vm.provision "ansible" do |ansible|
        #   ansible.playbook = "kubernetes-setup/master-playbook.yml"
        #   #ansible.verbose = "v"
        #   ansible.extra_vars = {
        #       node_ip: "192.168.50.10",
        #   }
        # end
    end

end

My versions
vagrant --version
Vagrant 2.2.14
vagrant plugin install vagrant-google:
Installed the plugin 'vagrant-google (2.7.0)'!
Laptop: MacOS 10.15

[azmng]

I guess you should get rid of quotes, below example works for me:

google.external_ip = false
google.use_private_ip = true