I changed the Region of the AWS EC2 instance, but the new Region instance is not visible from the IP address or DNS.

I changed the Region from U.S. Virginia to EU Frankfurt in AWS EC2 and moved the instance in snapshot AMI.
However, a new instance of EU Frankfurt does not display the site when accessing the browser with Public DNS or IPv4 Public IP.
Is it because you have not stopped the old pre-migration instance?
As for the instance of WordPress (bitnami), I am having trouble accessing the management screen as well.

I thought I needed to associate EIP from Elastic IPs, but I don't think EIP from Elastic IPs is the solution to the above problem because I didn't associate EIP with the original U.S. Virginia instance.

I'd like to do something about it because I've received a notice that will be retired in a few days, but does anyone know about it's?
Thank you for your cooperation.