Help me change the instance type from m5d.xlarge to m5a.2xlarge

Hi, since you already stopped the instance, the other option is that hibernation mode is enabled.

To view if an instance is enabled for hibernation

• Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.
• In the navigation pane, choose Instances.
• Select the instance and, on the Details tab, in the Instance details section, inspect Stop-hibernate behavior. Enabled indicates that the instance is enabled for hibernation.

You cannot disable it, so you ll need to launch a new instance from an image.

Hope it helps ;)