Read replica creation fails for AWS Postgresql using either the id or identifier from the source db

Terraform Providers AWS
1

I’ve tried using both the identifier and the id for the source db, but both fail with this error:

aws_db_instance.rds_instance: Still creating... [14m20s elapsed]
aws_db_instance.rds_instance: Creation complete after 14m25s [id=db-M3COF64VUY3YAPLEDHRCSBL2WQ]
╷
│ Error: creating RDS DB Instance (read replica) (terraform-20231231212917764100000001): DBInstanceNotFound: The source instance could not be found: rds-db
│ 	status code: 404, request id: 87ed0efb-32aa-4c38-9916-410927b412e4
│ 
│   with aws_db_instance.example_read_replica,

Here’s my code:

resource "aws_db_instance" "rds_instance" {
  engine               = "postgres"
  engine_version       = "15.4"
  instance_class       = "db.t3.micro"
  identifier            = "rds-db"
  username             = "rootuser"
  password             = "adminpwd"
  parameter_group_name = "pg15"
  backup_retention_period = 5
  multi_az              = true
  publicly_accessible  = true
  vpc_security_group_ids = [aws_security_group.rds_sg.id]
  db_subnet_group_name  = aws_db_subnet_group.rds_db_subnet_group.name
  allocated_storage = 20
  skip_final_snapshot = true
  tags = {
    Name = "rds-db"
  }
}


resource "aws_db_instance" "example_read_replica" {
  replicate_source_db = "rds-db"
  # replicate_source_db = aws_db_instance.rds_instance.id

  # Set to false for read replica
  multi_az = false
  instance_class       = "db.t3.micro"
}