I am trying to create an RDS Custom with SQL Server 2019 CU 22 Developer edition, but it fails with the following error:

You can't create the DB instance because of incompatible resources. The creation failed for DB instance rds-custom-dev-edition in AWS account _________. The credentials have expired. Retry initiating the database instance creation.

I’ve created an EC2 instance, installed SQL Server 2019 dev edition, installed CU 22 (tried also with 24) which are the supported versions by AWS RDS,
and added permissions to NT AUTHORITYSYSTEM, and shut down the instance with sysprep as required.

I than created a CEV,
created an IAM Role with the following permissions:

• AdministratorAccess
• AmazonRDSCustomInstanceProfileRolePolicy
• AmazonRDSFullAccess

I also created a KMS key.

and when I try to create an RDS Custom with those resources, I use standard configuration but it fails again and again, and I have no idea why…