Internal IP is use by HTTP internal load balance, but IP address show "none"

I created an Internal HTTP Load balance by the code below.

I can see Internal HTTP Load balance is running with internal IP(var.my_iip)

But in VPC network > IP addresses, the "in use by" of internal IP(var.my_iip) is "none"

Why not "Forwarding rule http-ife"? and how to make it right?(to prevent someone delete this IP cuz it seem no in use)

resource "google_compute_address" "ilb-iip" {
  name         = "ilb-iip"
  address      = var.my_iip
  address_type = "INTERNAL"
  purpose      = "SHARED_LOADBALANCER_VIP"
  subnetwork   = var.my_subnetwork
}
resource "google_compute_forwarding_rule" "http-ife" {
  name                  = "http-ife"
  ip_address            = google_compute_address.ilb-iip.self_link
  ip_protocol           = "TCP"
  load_balancing_scheme = "INTERNAL_MANAGED"
  network               = var.my_network
  port_range            = "80"
  subnetwork            = var.my_subnetwork
  target                = google_compute_region_target_http_proxy.target.id
  region                = var.my_region
  depends_on            = [google_compute_subnetwork.lb_subnet]
}