Five module limit?

//  Serial.println("present S_HUM");
  esp.present(CHILD_ID_HUM, S_HUM);

//  Serial.println("present S_TEMP");
  esp.present(CHILD_ID_TEMP, S_TEMP);

          esp.present(1, S_DIGITAL_OUTPUT);
          esp.present(2, S_DIGITAL_OUTPUT);
          esp.present(3, S_DIGITAL_OUTPUT);
          esp.present(4, S_DIGITAL_OUTPUT);

/*
 V2.0 - small fix
 
 Created by Igor Jarc <admin@iot-playground.com>
 See http://iot-playground.com for details
 
 This program is free software; you can redistribute it and/or
 modify it under the terms of the GNU General Public License
 version 2 as published by the Free Software Foundation.
 */
#include <Esp8266EasyIoT.h>
#include <SoftwareSerial.h> 
#include <DHT.h>  

#define CHILD_ID_HUM 0
#define CHILD_ID_TEMP 1
#define HUMIDITY_SENSOR_DIGITAL_PIN 2

#define SEND_INTERVAL  1000 * 30 // 30S  

        #define RELAY_1  6  // Arduino Digital I/O pin number for first relay (second on pin+1 etc)
        #define RELAY_ON 1  // GPIO value to write to turn on attached relay
        #define RELAY_OFF 0 // GPIO value to write to turn off attached relay

Esp8266EasyIoT esp; 

SoftwareSerial serialEsp(10, 11);


DHT dht;
float lastTemp;
float lastHum;

Esp8266EasyIoTMsg msgHum(CHILD_ID_HUM, V_HUM);
Esp8266EasyIoTMsg msgTemp(CHILD_ID_TEMP, V_TEMP);

unsigned long startTime;

void setup()
{
  serialEsp.begin(9600);
  Serial.begin(115200);  

  Serial.println("EasyIoTEsp init");

  //esp.begin(NULL, 3, &serialEsp, &Serial);
         esp.begin(incomingMessage, 3, &serialEsp, &Serial);

        
  //esp.begin(NULL, &serialEsp);
  dht.setup(HUMIDITY_SENSOR_DIGITAL_PIN); 

  pinMode(13, OUTPUT);

          pinMode(RELAY_1, OUTPUT);
          pinMode(RELAY_1 + 1, OUTPUT);
          pinMode(RELAY_1 + 2, OUTPUT);
          pinMode(RELAY_1 + 3, OUTPUT);

          
//  Serial.println("present S_HUM");
  esp.present(CHILD_ID_HUM, S_HUM);

//  Serial.println("present S_TEMP");
  esp.present(CHILD_ID_TEMP, S_TEMP);

          esp.present(1, S_DIGITAL_OUTPUT);
          esp.present(2, S_DIGITAL_OUTPUT);
          esp.present(3, S_DIGITAL_OUTPUT);
          esp.present(4, S_DIGITAL_OUTPUT);

  startTime = millis()+SEND_INTERVAL;
}

void loop()
{  
            esp.process(); 
  while(!esp.process());

  if (IsTimeout())
  {
    startTime = millis();

    float temperature = dht.getTemperature();
    if (isnan(temperature)) {
      Serial.println("Failed reading temperature from DHT");
    } 
    else if (temperature != lastTemp) 
    {
      lastTemp = temperature;
      esp.send(msgTemp.set(temperature, 1));
      Serial.print("T: ");
      Serial.println(temperature);
    }
  
    while(!esp.process());
  
    float humidity = dht.getHumidity();
    if (isnan(humidity)) {
      Serial.println("Failed reading humidity from DHT");
    } 
    else if (humidity != lastHum) 
    {
      lastHum = humidity;
      esp.send(msgHum.set(humidity, 1));
      Serial.print("H: ");
      Serial.println(humidity);
    }
  }
}

boolean IsTimeout()
{
  unsigned long now = millis();
  if (startTime <= now)
  {
    if ( (unsigned long)(now - startTime )  < SEND_INTERVAL ) 
      return false;
  }
  else
  {
    if ( (unsigned long)(startTime - now) < SEND_INTERVAL ) 
      return false;
  }

  return true;
}

// below from 4 relays
void incomingMessage(const Esp8266EasyIoTMsg &message) {
  // We only expect one type of message from controller. But we better check anyway.

  Serial.println("New message");
  if (message.type==V_DIGITAL_VALUE) {
    // Change relay state
    digitalWrite(message.sensor-1+RELAY_1, message.getBool()?RELAY_ON:RELAY_OFF);

    Serial.print("Incoming change for sensor:");
    Serial.print(message.sensor);
    Serial.print(", New status: ");
    Serial.println(message.getBool());
  } 
}