Midi.h MIDIUSB doesn't work for 'write'

Other Hardware Audio
10

OK, so in version 5.0.2 it does work ! yahoo. I mean everything but the midi-thru, but i do that manually anyway, it wasn't reliable. Had to remove version 4.3.1 or the whole thing won't compile properly of course. For completions sake

USBMIDI_CREATE_DEFAULT_INSTANCE();

#define LED 3
uint8_t channel = 1;

void handleNoteOn(byte inChannel, byte inNumber, byte inVelocity) {
  MIDI.sendNoteOn(inNumber, inVelocity, inChannel);
  analogWrite(LED, inVelocity * 2);
}
void handleNoteOff(byte inChannel, byte inNumber, byte inVelocity) {
  MIDI.sendNoteOff(inNumber, inVelocity, inChannel);
  analogWrite(LED, 0);
}

void setup() {
  pinMode(LED, OUTPUT);
  analogWrite(LED, 200);
  delay(1000);
  analogWrite(LED, 0);

  MIDI.begin();
  MIDI.turnThruOff();
  MIDI.setHandleNoteOn(handleNoteOn);
  MIDI.setHandleNoteOff(handleNoteOff);
}

void loop() {
  static uint32_t moment = millis();
  static bool noteon = true;
  if (millis() - moment > 2000) {
    moment = millis();
    if (noteon) MIDI.sendNoteOn(64, 127, channel);
    else MIDI.sendNoteOff(64, 0, channel);
    noteon = !noteon;
  }
  MIDI.read();
}

Thanks all !