available returns true even after reading.

test.ino

#include <nRF24L01.h>
//#include <printf.h>
#include <RF24.h>
#include <RF24_config.h>

// This is test code I am trying out using library 
#include <nRF24L01.h>
//#include <printf.h>
#include <RF24.h>
#include <RF24_config.h>
#include <SPI.h>

#include "Packet.h" //My own data structures. 

RF24 nrf24(A2,A0);
uint8_t addresses[][6]={"Node1","Node2"};

#define TX 0//has been set as tx

Advertise* adv;
Advertise a;
void setup() {

Serial.begin(4800);
Serial.println("Hello");
    if(!nrf24.begin())
      {
        Serial.println("failed to intialise");
      }
    nrf24.setCRCLength(RF24_CRC_8);
    nrf24.setDataRate(RF24_250KBPS);
    nrf24.setChannel(10);
    nrf24.setPALevel(RF24_PA_MAX);

#if (TX == 1)

  a.dev_Id=143;
  a.token_Id=7676;
  a.adv_type= PINGTEST;
  adv=&a;
    
    nrf24.openWritingPipe(addresses[1]);
    nrf24.setPayloadSize(sizeof(Advertise));
#else    //reveiver pipe setup
    nrf24.openReadingPipe(1,addresses[1]);       
    nrf24.setPayloadSize( sizeof(Advertise));
#endif 
nrf24.setAutoAck(false);
Serial.println("Setup done");
}

void loop() {
#if  (TX == 1)      //transmitter part
  Serial.println("sending Adv..");
  nrf24.write( (uint8_t*)adv, sizeof(Advertise));
   
     
//    nrf24.send((uint8_t*)adv,sizeof(Advertise));
//     Serial.println("read failed");

     Serial.print("Dev ID: ");
   Serial.println(adv->dev_Id);
   Serial.print("Token ID: ");
   Serial.println(adv->token_Id);
   Serial.print("Adv type: ");
   Serial.println(adv->adv_type);

#else //receiver part

   nrf24.startListening();
   Serial.println("waiting..");
   Advertise a;
   uint8_t len= sizeof(a);
//   while(!nrf24.available())
//   {
//       nrf24.read( &a, len );
//   }
   
   unsigned long started_waiting_at =millis();
   bool timeout=false;
   while ( !nrf24.available() ){                             // While nothing is received
      if ((millis() - started_waiting_at) > 5000 ){            // If waited longer than 200ms, indicate timeout and exit while loop
          timeout = true;
          break;
      }else
          timeout=false;
    }
     if ( timeout ){                                             // Describe the results
        Serial.println(F("Failed, response timed out."));
    }else{
   Advertise a;
   uint8_t len= sizeof(a);    
  while ( nrf24.available() ){
  
  Serial.println("woow some data .. **************************");
  nrf24.read( &a, len );
  
   Serial.print("Dev ID: ");
   Serial.println(a.dev_Id);
   Serial.print("Token ID: ");
   Serial.println(a.token_Id);
   
   Serial.print("Adv type: ");
   Serial.println(a.adv_type);
 
  a.dev_Id=0;
  a.token_Id=0;
  a.adv_type= 0;

  Serial.println("___________has the buffered erased?____________");
   Serial.print("Dev ID: ");
   Serial.println(a.dev_Id);
   Serial.print("Token ID: ");
   Serial.println(a.token_Id);
   Serial.print("Adv type: ");
   Serial.println(a.adv_type);
 
  Serial.println("___________are all these zeroed?____________");
  }
 }
 
 Serial.print("nrf available test: "); Serial.println(nrf24.available());
// Serial.print("timeout :");
// Serial.println(timeout);
//nrf24.stopListening();
#endif
delay(2000);
}