Inconsistant behavior of aws cloudwatch rule

Question

I'm using Terraform automation to create a CloudWatch rule that triggers an SNS topic when any ec2 instance changes its states.

The issue is that when I run the automation codebuild with new updates the rule sometimes triggers the SNS topic and sometimes not, in order to make it work I change the rule name or I play with the pattern of the rule manually like from this:

{
  "detail-type": [
    "EC2 Instance State-change Notification"
  ],
  "source": [
    "aws.ec2"
  ]
}

To this:

{
  "source": [
    "aws.ec2"
  ],
  "detail-type": [
    "EC2 Instance State-change Notification"
  ]
}

Any Idea why I'm facing this?