Blynk login timeout problem

Blynk_login_timeout.ino

/*************************************************************
  Arduino Nano with optiboot and ESP8266 in AT mode

  Login timeout problem
*/
#define BLYNK_PRINT Serial

#include <BlynkSimpleShieldEsp8266.h>
#include <ESP8266_Lib.h>
#include <SoftwareSerial.h>

const char auth[] = "";
const char ssid[] = "";
const char pass[] = "";
const char host[] = "";

SoftwareSerial EspSerial(4, 2); // RX, TX
ESP8266 Wifi(&EspSerial);

BlynkTimer timer;
// I only define timer2 to use up a lot of memory.
// Without the second timer, the sketch only uses 56% memory and its working correctly
// Uncommenting this line rises the memory useage to 71% and the login time out problem occurs
//BlynkTimer timer2;

void setup()
{
  Serial.begin(9600);
  EspSerial.begin(9600);
  delay(10);
  Blynk.begin(auth, Wifi, ssid, pass, host);
  delay(200);

  timer.setInterval(10000, requestTime);
}

void loop()
{
  Blynk.run();
  timer.run();
}

void requestTime() {
  Serial.println("Requesting time");
  Blynk.sendInternal("rtc", "sync");
}

BLYNK_WRITE(InternalPinRTC) {
  unsigned long blynkTime = param.asLong();
  Serial.print("Time sync: OK ");
  Serial.print(blynkTime);
  Serial.println();
}