MAX7219 and a common-anode 5x7 bicolor matrix wiring

Why does this happens? (video)

The first matrix is well lit... but the second one I just can't make it light up correctly.

This is the function I'm using. I could also notice a small interval between the end of the first matrix and the beginning of the second... why?

void singleLedMultipleDrivers() {
  //while(dev<3){
  for(int mat=0;mat<lc.getDeviceCount();mat++) { 
     for(int row=0;row<8;row++) {
      for(int col=0;col<8;col++) {
        delay(delaytime);
        lc.setLed(mat,row,col,true);
        delay(delaytime);
        for(int i=0;i<col;i++) {
          lc.setLed(mat,row,col,false);
          delay(delaytime);
          lc.setLed(mat,row,col,true);
          delay(delaytime);
        } //on-off
      } //col
    } //row
    //dev++;
  }// while
  //dev = 1;
}