Voice module v3 arduino nano

Hello,
I am trying to get the readings of LDR on 0.96" Adafruit OLED Display using voice module V3 (voice commands). The display should start/stop displaying LDR readings when I say "on" and "off", it should run in loop. I have trained the voice module with that command.
I am even able to turn on/off led with that command. But after changing the code to read the LDR values as:

#include <SoftwareSerial.h>
#include "VoiceRecognitionV3.h"
#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
int sensorPin = A0; // select the input pin for ldr
int sensorValue = 0;


#define OLED_RESET 4 // not used / nicht genutzt bei diesem Display
Adafruit_SSD1306 display(OLED_RESET);

 char inChar;
 String string;
/**        
  Connection
  Arduino    VoiceRecognitionModule
   2   ------->     TX
   3   ------->     RX
*/
VR myVR(2,3);    // 2:RX 3:TX, you can choose your favourite pins.

uint8_t records[7]; // save record
uint8_t buf[64];



#define OnRecord    (0)
#define OffRecord   (1) 

/**
  @brief   Print signature, if the character is invisible, 
           print hexible value instead.
  @param   buf     --> command length
           len     --> number of parameters
*/
void printSignature(uint8_t *buf, int len)
{
  int i;
  for(i=0; i<len; i++){
    if(buf[i]>0x19 && buf[i]<0x7F){
      Serial.write(buf[i]);
    }
    else{
      Serial.print("[");
      Serial.print(buf[i], HEX);
      Serial.print("]");
    }
  }
}

/**
  @brief   Print signature, if the character is invisible, 
           print hexible value instead.
  @param   buf  -->  VR module return value when voice is recognized.
             buf[0]  -->  Group mode(FF: None Group, 0x8n: User, 0x0n:System
             buf[1]  -->  number of record which is recognized. 
             buf[2]  -->  Recognizer index(position) value of the recognized record.
             buf[3]  -->  Signature length
             buf[4]~buf[n] --> Signature
*/
void printVR(uint8_t *buf)
{
  Serial.println("VR Index\tGroup\tRecordNum\tSignature");

  Serial.print(buf[2], DEC);
  Serial.print("\t\t");

  if(buf[0] == 0xFF){
    Serial.print("NONE");
  }
  else if(buf[0]&0x80){
    Serial.print("UG ");
    Serial.print(buf[0]&(~0x80), DEC);
  }
  else{
    Serial.print("SG ");
    Serial.print(buf[0], DEC);
  }
  Serial.print("\t");

  Serial.print(buf[1], DEC);
  Serial.print("\t\t");
  if(buf[3]>0){
    printSignature(buf+4, buf[3]);
  }
  else{
    Serial.print("NONE");
  }
  Serial.println("\r\n");
}

void setup()
{
  /** initialize */
  myVR.begin(9600);
  pinMode(13, OUTPUT);
  
  // initialize with the I2C addr 0x3C / mit I2C-Adresse 0x3c initialisieren
  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
  display.display();
  
  display.clearDisplay();
 
  display.setTextColor(INVERSE); 
  
  Serial.begin(115200);
  Serial.println("Elechouse Voice Recognition V3 Module\r\nControl LED sample");
  
  pinMode(sensorPin, INPUT);
    
  if(myVR.clear() == 0){
    Serial.println("Recognizer cleared.");
  }else{
    Serial.println("Not find VoiceRecognitionModule.");
    Serial.println("Please check connection and restart Arduino.");
    while(1);
  }
  
  if(myVR.load((uint8_t)OnRecord) >= 0){
    Serial.println("startRecord loaded");
  }
  
  if(myVR.load((uint8_t)OffRecord) >= 0){
    Serial.println("endRecord loaded");
  }
}

void loop()
{
  int ret;
  ret = myVR.recognize(buf, 50);
  if(ret>0){
    
    
    switch(buf[1]){
      case OnRecord:
       display.clearDisplay();
       sensorValue = analogRead(sensorPin);
       display.setCursor(30,0); 
       display.setTextSize(1);
       display.print("LDR Reading:");
       display.setCursor(30,10); 
       display.setTextSize(2);
       display.print(sensorValue);
       delay(500);           
     
       break;
      case OffRecord:
       display.clearDisplay();
       
       break;
       
      default:
        Serial.println("Record function undefined");
        break;
    }
    display.display();
    printVR(buf);
  }
}

The OLED in this case will start the display when I say on and freezes on the first reading with no change in display. Also there is no response when I say the second command.

There is a fault in my code. I am trying to run a loop inside switch case. I am a beginner in programming, can somebody please help me out?

Thanks in advance

Any Idea how to solve this guys!! Its really important for me