The network interface is lost after the instance is restarted, and the elastic IP address is lost

The trick with IP addresses and EC2 instances is that the auto-assigned Public IPs will be lost on restart. To ensure you maintain possession of a specific IP address, you need to allocate the EIP with public address first. Then you create the EC2 instance and associate it to the already allocated EIP. This IP can now be durable across restarts and even be moved to another EC2 instance The section on public IPv4 addresses will be a good read for a more detailed explanation. https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-instance-addressing.html