Serial.println() was not printing on serial monitor

Projects General Guidance
45 
void setup()
{
  // put your setup code here, to run once:
  Serial.begin(115200);

  while (!Serial)
  {
    ; // Wait for serial to connect
  }

  delay(1000);
  Serial.println("setup()");
}

void loop()
{
  static uint32_t i = 0 ;
  Serial.print("loop()");  // should start at 0
  Serial.println( i++ ) ;
  delay( 1000) ;
}

Serial monitor:
loop()1
loop()2
loop()3
loop()4
loop()5
loop()6
loop()7
loop()8