RDS automatic minor version upgrades should be enabled

How to fix it

In the console

RDS → Databases → the DB instance → Modify → Maintenance

Enable auto minor version upgrade

Selected

Maintenance window

A time when the instance can be offline while an upgrade is applied

With the AWS CLI

aws rds modify-db-instance --db-instance-identifier <db-instance-id> --auto-minor-version-upgrade --region <region>

With Terraform

resource "aws_db_instance" "this" {
  auto_minor_version_upgrade = true
  instance_class             = var.instance_class
}