Unable to retrieve iBeacon UUID (ESP32 BLE Scanner) - bluetooth-lowenergy

Question

I have been using the ESP32 to scan for nearby iBeacon but I was unable to retrieve the UUID of beacons. The serial monitor keeps displaying "N/a". However, I was able to get the UUIDs of beacons when using the normal android BLE scanner app. Is there anything missing in my code?
/*
Based on Neil Kolban example for IDF: https://github.com/nkolban/esp32-snippets/blob/master/cpp_utils/tests/BLE%20Tests/SampleScan.cpp
Ported to Arduino ESP32 by Evandro Copercini
*/
#include <BLEDevice.h>
#include <BLEUtils.h>
#include <BLEScan.h>
#include <BLEUUID.h>
#include <BLEAdvertisedDevice.h>
BLEScan* pBLEScan;
int scanTime = 5; //In seconds
class MyAdvertisedDeviceCallbacks: public BLEAdvertisedDeviceCallbacks
{
void onResult(BLEAdvertisedDevice advertisedDevice)
{
//Print Name
Serial.print("Name :");
if (advertisedDevice.haveName())
{
Serial.println(advertisedDevice.getName().c_str());
}
else
{
Serial.println("N/a");
}
//Print RSSI
Serial.print("RSSI :");
Serial.println(advertisedDevice.getRSSI());
//Print UUID
Serial.print("UUID :");
if (advertisedDevice.haveServiceUUID())
{
Serial.println(advertisedDevice.getServiceUUID().toString().c_str());
}
else
{
Serial.println("N/a");
}
Serial.println("");
}
};
void setup() {
Serial.begin(115200);
Serial.println("Scanning...");
}
void loop() {
BLEDevice::init("");
pBLEScan = BLEDevice::getScan(); //create new scan
pBLEScan->setActiveScan(true); //active scan uses more power, but get results faster
pBLEScan->setAdvertisedDeviceCallbacks(new MyAdvertisedDeviceCallbacks());
BLEScanResults foundDevices = pBLEScan->start(scanTime);
Serial.print("Devices found: ");
Serial.println(foundDevices.getCount());
Serial.println("Scan done!");
delay(1000);
}