How to prevent a specific exception from being retried in RabbitMQ - spring-boot

Question

In my Spring Boot project I'm using RabbitMQ for messaging and have two exceptions CustomExceptionA and CustomExceptionB. I want my CustomExceptionA to be retried n times and CustomExceptionB not to retry but directly sent to DLQ.
Below are my configurations:-
yaml file
spring:
rabbitmq:
listener:
simple:
default-requeue-rejected: false
retry:
enabled: true
initial-interval: 2s
max-attempts: 3
max-interval: 2s
multiplier: 1
Configuration file
#Bean
public SimpleRabbitListenerContainerFactory rabbitListenerContainerFactory(ConnectionFactory connectionFactory,
SimpleRabbitListenerContainerFactoryConfigurer configurer) {
SimpleRabbitListenerContainerFactory factory = new SimpleRabbitListenerContainerFactory();
configurer.configure(factory, connectionFactory);
factory.setErrorHandler(errorHandler());
return factory;
}
#Bean
public ErrorHandler errorHandler() {
return new ConditionalRejectingErrorHandler(customExceptionStrategy());
}
#Bean
FatalExceptionStrategy customExceptionStrategy() {
return new CustomFatalExceptionStrategy();
}
-----------------------------------------------------------------------------------------------------------------------------
#Component
public class CustomFatalExceptionStrategy extends ConditionalRejectingErrorHandler.DefaultExceptionStrategy {
#Override
public boolean isFatal(Throwable throwable) {
return (throwable.getCause() instanceof CustomExceptionB);
}
}
According to the blog : https://www.baeldung.com/spring-amqp-error-handling mechanism should work but for some reason it is not working for me.
Someone please look at the issue.