CloudFormation fails with Route53 RecordSet and ApiGatewayV2 Domain - amazon-web-services

Question

I am using Serverless to create a WebSocket API with AWS. I have added the following additional CloudFormation resources inside the serverless.yml file:
Resources:
ApiGatewayDomain:
Type: AWS::ApiGatewayV2::DomainName
Properties:
DomainName: ${opt:id}.example.com
DomainNameConfigurations:
- EndpointType: REGIONAL
CertificateArn: arn:aws:acm:eu-central-1:<REDACTED>:certificate/<REDACTED>
ApiGatewayBasePathMapping:
Type: AWS::ApiGatewayV2::ApiMapping
Properties:
DomainName: # ${opt:id}.example.com
Ref: ApiGatewayDomain
ApiId:
Ref: "WebsocketsApi"
Stage: ${opt:stage, 'dev'}
DependsOn:
- WebsocketsDeployment${sls:instanceId}
- WebsocketsDeploymentStage
Route53RecordSet:
Type: AWS::Route53::RecordSet
Properties:
Type: A
HostedZoneId: <REDACTED>
Name:
Ref: ApiGatewayDomain
AliasTarget:
DNSName: # <REDACTED>.execute-api.eu-central-1.amazonaws.com.
Fn::Join:
- ""
-
- Fn::GetAtt: [ApiGatewayDomain, RegionalDomainName]
- "."
HostedZoneId: # Z1U9ULNL0V5AJ3
Fn::GetAtt: [ApiGatewayDomain, RegionalHostedZoneId]
DependsOn:
- ApiGatewayDomain
I want to achieve, that the deployment of a stack registers a custom api gateway domain (works), sets up the path mapping (works) and adds a Route53RecordSet (only works with concrete values).
I cannot figure out what I am doing wrong and always get an internal error from Route53. If I comment out the Fn::Join and Fn::GetAtt blocks for DNSName and HostedZoneId and use concrete values, everything works as expected. Am I missing something or is this simply an error with CloudFormation and Route53?