Instance Status check failed after change from t2.2xlarge to t3.2xlarge

Hi there,

Thank you for reaching out with your issue.

Before you migrate to our new generation instance types(T3's) there are number of prerequisites that must be met on the instance.

You would need to ensure that the NVMe and ENA drivers are installed before changing the ENA flag and the instance type.

This process only works for EBS backed instances and before following the steps in this procedure, I recommend that you create a backup of the instance in the form of an AMI.

To install the drivers, please see the AWS documentation[1].

You must also ensure that part 1 to part 4 are completed :
Part 1: Installing and upgrading AWS PV drivers
Part 2: Installing and upgrading ENA
Part 3: Upgrading AWS NVMe drivers
Part 4: Updating EC2Config and EC2Launch

Note
When migrating to the latest generation instances, the static IP or custom DNS network settings on the existing ENI may be lost as the instance will default to a new Enhanced Networking Adapter device.

I hope the provided information helps.
Please review the provided documentation for more information.

Have a great day!

References:
[1] https://docs.aws.amazon.com/AWSEC2/latest/WindowsGuide/migrating-latest-types.html