A digital payment gateway system is running in AWS which serves thousands of businesses worldwide. It is hosted in an Auto Scaling Group of EC2 instances behind an Application Load Balancer with an Amazon RDS database in a Multi-AZ deployment configuration. The company is using several CloudFormation templates in deploying the new version of the system. The AutoScalingRollingUpdate policy is used to control how CloudFormation handles rolling updates for their Auto Scaling group which replaces the old instances based on the parameters they have set. Lately, there were a lot of failed deployments which has caused system unavailability issues and business disruptions. They want to find out what's preventing their Auto Scaling group from updating correctly during a stack update. In this scenario, how should the DevOps engineer troubleshoot this issue? (Select THREE.)