karate does not return all variables that were defined (using def) in the 'called' feature

I have the following file karate-config-test.js

 function fn() {    
  var env = karate.env; // get system property 'karate.env'
  var baseUrl = "http://localhost:5000"
  var config = {
    env: env,
    baseUrl: baseUrl
  };

  //open connection to message broker (mqtt, amqp)
  var async_message = karate.callSingle('classpath:com/connect/apitests/commons/async_message/async_message.feature', config);
  config.mqtt = async_message.mqtt
  config.amqp = async_message.amqp
 
  return config;
}

And the following feature async_message.feature

@ignore

Feature: utility that instance async message broker
Background:
 
  * url baseUrl 

Scenario: Set instance of a class AmqpUtils And MqttUtils
    * def amqp = 'pippo'
   
Scenario: Set instance of a class MqttUtils
    * def mqtt = 'pluto'
 

when i check the value of the variable async_message i see the variables of one scenario but not both, for example I saw only mqtt. Why is this happening? In karate documentation I read

• All variables that were defined (using def) in the 'called' script would be returned as 'keys' within a JSON-like object.

Karate is designed so that when you do a call of any kind, the last Scenario is what is considered for returning variables.

In other words, the best practice is to call one Scenario at a time. You can use tags to "isolate" scenarios if you don't like splitting scenarios into different files.