Having trouble controlling 3 Row Seven Segment with 4 shift register 74hc595

Using Arduino LEDs and Multiplexing
47

yes i change, length of digit is 6 digit/rows,
and i change to this value too:

byte displayBuffer[3][6] =    //digit to display in each position
{
  {1, 1, 1, 1, 1, 1},
  {2, 2, 2, 2, 2, 2},
  {3, 3, 3, 3, 3, 3}, 
};