ERROR: Can't change netmask

Where doing a school project trying to do topologies using Google Cloud as the cloud and Terraform as the way to administrate every aspect of the virtual machine and network creation.
When we try to assign IP address on the machines we get a default netmask (/32) every time we try to create a new machine even when we are giving guidelines on the code to give us a /24.
This is the configuration of the network and subnetworks on the main.tf:

resource “google_compute_network” “vpc_network” {
name = “t-network-hyperion”
auto_create_subnetworks = false
}

resource “google_compute_subnetwork”
“subnet_network” {
name = “subnet-hyperion”
network = google_compute_network.vpc_network.self_link
ip_cidr_range = “192.168.0.0/24”
region = “us-central1”
}
We tried changing the net mask using /16, /24, /28.
Every time we have changed the configuration we have destroyed the previews version and created new ones but it never changes. We are using this version of the provider:
terraform {
required_providers {
google = {
source = “hashicorp/google”
version = “4.57.0”
}
}
}
We’re struggling because we don’t know well what could be the solution. Any help may help us to get a solution on this topic. If anybody need to see more part of the code we would be on line.