Not able to connect to rabbitmq instance using Java – Docker

Currently I have two rabbitmq docker containers in my environment. One of them has the external port set to 5672 and another one is using 5673. From my java program (which is not dockerized) I am trying to connect to the container listening on 5673 by using the amqp-client maven library.
The code looks something like this:

ConnectionFactory factory = new ConnectionFactory();
Connection connection = factory.newConnection("amqp://guest:guest@localhost:5673");

Channel channel = connection.createChannel();
channel.queueDeclare("region", true, false, false, null);

DefaultConsumer consumer =
    new DefaultConsumer(channel) {

      @Override
      public void handleConsumeOk(String consumerTag) {
        super.handleConsumeOk(consumerTag);
      }

      @Override
      public void handleDelivery(
          String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body)
          throws IOException {
        String message = new String(body, StandardCharsets.UTF_8);
        log.info(message);
      }
    };

channel.queueBind("region", "gas_region", "");
channel.basicConsume("region", true, consumer);

The problem I have is that my Java program keeps connecting to the 5672 instance instead of the one listening on 5673. I noticed that because I see the created queue in the 5672 instance instead of the other one and also my program doesn’t find the configured exchange in the 5673 instance.
Does someone have any ideas on what could be the problem?

The docker compose configuration for my rabbitmq instances looks like this:

input_mb:
    image: rabbitmq:3-management
    hostname: rabbit1
    container_name: input_mb
    ports:
        - 5672:5672
        - 15672:15672
    volumes:
        - "./input_mb/rabbitmq.config:/etc/rabbitmq/rabbitmq.config"
        - "./input_mb/definitions.json:/etc/rabbitmq/definitions.json"
    networks:
        - common_network

output_mb:
    image: rabbitmq:3-management
    hostname: rabbit2
    container_name: output_mb
    ports:
        - 5673:5672
        - 15673:15672
    volumes:
        - "./output_mb/rabbitmq.config:/etc/rabbitmq/rabbitmq.config"
        - "./output_mb/definitions.json:/etc/rabbitmq/definitions.json"
    networks:
        - common_network