convertSendAndReceive() returns null Object

Question

I have been looking for a solution since morning. Why is it returning null rather than an Object? Any ideas

Consumer part takes the message but the response is Null with the convertSendAndReceive() method.

RabbitMQProducer.java

 private static final long DEFAULT_REPLY_TIMEOUT = 10000;

 public Object sendJsonMessage(Card card){
    rabbitTemplate.setReplyTimeout(DEFAULT_REPLY_TIMEOUT);
    log.info(String.format("Message sent -> %s", card.toString()));

   return rabbitTemplate.convertSendAndReceive(exchange,routingKey, card);
}

Controller

 @PostMapping("/addCards")
 public ResponseEntity <String> addCards(@Valid @RequestBody Card card ){
    Object object = producer.sendJsonMessage(card);

    System.out.println( "OBJECT :" +    object);
    return ResponseEntity.ok("Json message sent to RabbitMQ ..." + card.getFirstName());
}

Output

OBJECT :null