Blynk-cloud:80 error I need help deadline is near

Dear Blynk users,
I am using blynk for the first time.
the hardware that I am using is as below: Arduino uno, Sim800l v2.0, DHT11 (temperature and humidity sensor), blynk library version 0.5.4, arduino IDE 1.8.7.
My sim800l module is brand new so a setup the AT commands in order to be to use the gprs feature, i setup the baud rate of it into 9600.
then I followed the Blynk example found in the library for this module.(the code below).
the modem initialized, the connection to internet was OK, but the serial monitor then started to give “Blynk-cloud: 80”.
then I changed the module baud rate to 115200, the module didn’t initialize and it give “SIM is missing”
please help me fix this issue since the deadline for this project is two days a head.
thank you.

#include <SoftwareSerial.h>

#define BLYNK_PRINT Serial


// Default heartbeat interval for GSM is 60
// If you want override this value, uncomment and set this option:

#include <TinyGsmClient.h>
#include <BlynkSimpleSIM800.h>
#include "dht.h"

// You should get Auth Token in the Blynk App.
// Go to the Project Settings (nut icon).
char auth[] = "d19403de357d4fa09c692b21316d1fdb";

// Your GPRS credentials
// Leave empty, if missing user or pass
char apn[]  = "touch";
char user[] = "";
char pass[] = "";

// Hardware Serial on Mega, Leonardo, Micro
//#define SerialAT Serial1

// or Software Serial on Uno, Nano
#include <SoftwareSerial.h>
SoftwareSerial SerialAT(3, 2); // RX, TX

TinyGsm modem(SerialAT);
#define dht_apin A0
dht DHT;

BlynkTimer timer;

// This function sends Arduino's up time every second to Virtual Pin (5).
// In the app, Widget's reading frequency should be set to PUSH. This means
// that you define how often to send data to Blynk App.
void sendSensor()
  float h = DHT.humidity;
  float t = DHT.temperature; 
  // You can send any value at any time.
  // Please don't send more that 10 values per second.
  Blynk.virtualWrite(V1, h);
  Blynk.virtualWrite(V0, t);

void setup()
  // Debug console


  // Set GSM module baud rate

  // Restart takes quite some time
  // To skip it, call init() instead of restart()
  Serial.println("Initializing modem...");

  // Unlock your SIM card with a PIN

  Blynk.begin(auth, modem, apn, user, pass);


  // Setup a function to be called every second
  timer.setInterval(2500L, sendSensor);

void loop()