TM1640 Matrix + ArrayBuffer first column of letter does not appear in scrolling text

Sorry long title...

I'm working with Chrome app (cause i've got custom font) with last firmware (2.05) on Pico board.
I discovered a strange behavior (not seen before)

I'm scrolling a text on a 8x8 led matrix with a TM1640 driver (a wemos matrix shield, chip and easy to drive)

I reuse an early script ( that was working, and working with this driver, not the first time i use it), this time i found the scroll jerky, so i slowed down the scroll and i identified what i was feeling...

the first column of a char is never seen, the buffer (i suppose) saw only the char with 2 column and more (not only one).
There is no missing column on the buffer, i have 8 column lighted

it happens on every letter (even if I delete my custom font) appearing from the right side.

It looks like the drawString does not draw the char if it is on the boarder...

in my code i use a setRotation() , i' tried without it, same pb.

any help?

frame 1 |frame 2 |frame 3
00000000|00000000|00000000
00000000|000000x0|00000x00
00000000|000000xx|00000xxx
00000000|000000x0|00000x00
00000000|000000x0|00000x00
00000000|000000x0|00000x00
00000000|0000000x|000000xx
00000000|00000000|00000000

i give my durty code to test

// sur la matrice TM1640:
/*
  pour TM1640
  CLK D5 -> B13
  DIN D7 -> B15
     3V3 -> 3V3
      5V -> Vout
     GND -> GND
  */
require("Font4x6").add(Graphics);

// crée le buffer graphique 8x8 en 1 bit
let g = Graphics.createArrayBuffer(8,8,1);

const phrases = ["Sourire aux cons","Aquiescer aux injonctions d'un supérieur","Mourir de honte","Mourir d'envie","Sourire aux jolies femmes","s'endormir devant la télévision"];

let phraseTot;
let compteur = 8;
let compteurTable = 0;
let longPhrase;
let first = true;

let verif = [];

function ecrit(){
  digitalPulse(LED2, true, 20);
  phraseTot = "À quoi bon, ";
  // tire la phrase une seule fois.
  let tirage;
  do { tirage = Math.floor(Math.random()*phrases.length)­;} while ( verif[tirage]== true );
  compteurTable++;
  verif[tirage] = true;
  phraseTot += phrases[tirage].toLowerCase()+".";
  longPhrase = g.stringWidth(phraseTot);
  if (compteurTable == phrases.length) {
    // reset de la table de verif
     verif = [];
    compteurTable = 0;
    console.log("reset verif[]");
  }
  console.log(phraseTot, longPhrase);
  compteur = 8;
  if (first) {
    setTimeout(envoieMatrice,500);
    first = false;
  }
}

function envoieMatrice() {
  // raccorde le bout de ligne suivant
  if (compteur < -longPhrase){
    // si au bout du texte
    ecrit();
  }
  // reset le buffer, ajoute la font, ecrit la chaine de caractères
  g.clear();
  g.setFont4x6();
  /* une fois font utilisée, on connait la longueur de la chaine*/
  longPhrase = g.stringWidth(phraseTot);
  compteur--;
  // ecrit la phrase
  g.drawString(phraseTot,compteur,0);
  console.log(compteur, longPhrase);
  g.setContrast(7); /* val entre 0 et 7 - TM1640*/
  g.setRotation(2,true); // TM1640
  // mise à jour du display
  g.flip();
  setTimeout(envoieMatrice, 500);
}

function onInit() {
  // importe font
  require("Font4x6").add(Graphics);
  require('Storage').eraseAll();
  USB.setConsole();
  // spi mosi=DIN, sck=CLOCK
  g = require("TM1640").connect({din: B15, clk: B13});
}

USB.setConsole();

best regards

éric