What is the problem?

CfnParameters cannot be used for the port value of a DatabaseInstance in aws-rds. The value requires only a number and valueAsNumber on a CfnParameter doesn't produce a valid number on synthesis.
"Port": "-1.8881545897088186e+289"
instead of
"ToPort": { "Ref": "DBPort" } (as it becomes for a security group)
https://docs.aws.amazon.com/cdk/api/v2/docs/aws-cdk-lib.aws_rds.DatabaseInstance.html

Reproduction Steps

const dbPort = new CfnParameter(this, 'DBPort', {
  type: 'Number',
  default: 5432
})

const postgresDb = new rds.DatabaseInstance(this, 'PostgresDb', {
      port: dbPort.valueAsNumber,
})

What did you expect to happen?

Expected that the generated cfn-template would have the port parameter as a reference to the cfn parameter

What actually happened?

The port parameter was set to a static value: -1.8881545897088186e+289

CDK CLI Version

2.0.0 (build 4b6ce31)

Framework Version

No response

Node.js Version

v16.9.1

OS

mac os

Language

Typescript

Language Version

No response

Other information

No response