Can't use the VPC UUID in the droplet creation

[tbhaxor]

I am getting the following error

│ Error: Error creating droplet: POST https://api.digitalocean.com/v2/droplets: 422 (request "e2bc39a0-cd6d-4624-b861-4101bf693adf") Failed to resolve VPC
│ 
│   with digitalocean_droplet.slave[0],
│   on droplet.tf line 16, in resource "digitalocean_droplet" "slave":
│   16: resource "digitalocean_droplet" "slave" {

for the following droplet droplet config

resource "digitalocean_droplet" "slave" {
  name     = "${var.prefix}-${var.region}-${random_integer.slave-suffix[count.index].result}"
  tags     = [var.tag-name]
  vpc_uuid = digitalocean_vpc.main.id
  count    = var.slave-count

  image = "debian-12-x64"
  size  = var.slave-size

  depends_on    = [digitalocean_vpc.main]
  droplet_agent = true
  monitoring    = true
  user_data     = <<-EOF_USERDATA
  service squid stop
  cat <<EOF > /tmp/done.txt
  Loadbalancer IP: ${digitalocean_loadbalancer.lb.ip}
  VPC ID: ${digitalocean_vpc.main.id}
  EOF
  EOF_USERDATA
}

This VPC UUID thing is actually working, I am using load balancer and it being created in that VPC

resource "digitalocean_loadbalancer" "lb" {
  name        = "${var.prefix}-lb"
  droplet_tag = var.tag-name
  vpc_uuid    = digitalocean_vpc.main.id
  region      = var.region
  size_unit   = var.lb-count

  forwarding_rule {
    entry_port      = 80
    entry_protocol  = "tcp"
    target_port     = 3128
    target_protocol = "tcp"
  }

  healthcheck {
    protocol = "tcp"
    port     = 3128
  }
}

I am taking example from https://registry.terraform.io/providers/digitalocean/digitalocean/latest/docs/resources/vpc#resource-assignment

[tbhaxor]

I have also tried urn instead of id. Just in case it takes urn. Still no luck

[tbhaxor]

When I omit vpc_uuid, it is working but not setting up droplets in desired vpc network.

[tbhaxor]

region        = var.region

Adding this fixed the code