Migrating a Windows Server Using Application Migration Service

Hi there, My customer have question in regarding Windows license, when he was migrating a Windows Server from on-prem to AWS. What he choose is license included, which means he is going to use Windows license provided by AWS. After the server reboot on AWS, AWS also recognize this server as a Windows server. However, when he was going to see the registration info of this server, it only showed the registration of on-prem server. That means, we are charging the customer by a rate of EC2 Windows, meanwhile the server is still registered using the pre-migration license.