Command is 'received' after 3-4 attempts

Projects General Guidance
2 
if (Serial.available() > 0) {
      // read the incoming byte:
      incomingByte = Serial.read();
      }



  while (Serial.available()) {
    char inChar = (char)Serial.read();

Think carefully again.

And code tags. Thanks for demonstrating why we ask you to use them.