(X2e) HelloWorld => reboot Arduino !

Dear
I’m using HelloWorld.py on a X2e Gateway. It’s strange since the arduino reboot average 75% of each sent. I don’t anderstand why ???
Here, the simple arduino code to read the data:

#include 

XBee xbee = XBee();
ZBRxResponse zbRx = ZBRxResponse();

void setup () {
 delay(100);
  Serial.begin(9600);
  xbee.setSerial(Serial);
 Serial.println("starting up yo!");
}

void loop () {
 xbee.readPacket();
 if (xbee.getResponse().isAvailable()) {
   if (xbee.getResponse().getApiId() == ZB_RX_RESPONSE) {
     xbee.getResponse().getZBRxResponse(zbRx);
                                         
     Serial.println("Got an rx packet!");
                                                                 
     if (zbRx.getOption() == ZB_PACKET_ACKNOWLEDGED) 
                Serial.println("packet acknowledged");                                  
      else 
                Serial.println("packet not acknowledged");
                                                                       
      for (int i = 0; i < zbRx.getDataLength(); i++) {
                Serial.print("payload [");
                Serial.print(i, DEC);
                Serial.print("] is ");
                Serial.println(zbRx.getData(i));
                }
   }
 }
}

Best regards.