如何修复pChart的多个系列条形图中的重叠条？

I'm using c-pChart library to draw charts, and generating some PDF files using mPDF library. I have to draw a multiple series bar chart. I did same as the example given in pChart website. But my bars are overlapping to each other.

I have searched through all the documentations of pChart as well as StackOverflow. But I couldn't find any resource that had this issue. The c-pChart I'm using is the latest version of pChart which is 2.1.4. I'm using PHP 7. Please refer to this git repo for c-pChart reference. https://github.com/szymach/c-pchart

require_once __DIR__ . '/libPDF/vendor/autoload.php';
require_once __DIR__ . '/vendor/autoload.php';

use CpChart\Chart\Pie;
use CpChart\Data;
use CpChart\Image;


$MyData = new Data();
$MyData->addPoints(array(1,2,16,12,8,3),"Probe 1");
$MyData->addPoints(array(3,12,15,8,5,-5),"Probe 2");
$MyData->addPoints(array(2,0,5,18,19,22),"Probe 3");

$MyData->setSerieTicks("Probe 2",4);
$MyData->addPoints(array("Jan","Feb","Mar","Apr","May","Jun"),"Labels");
$MyData->setSerieDescription("Labels","Months");
$MyData->setAbscissa("Labels");

$MyData->setAxisName(0,"Temperatures");

$myPicture = new Image(1000, 500, $MyData);
$myPicture->drawRectangle(0, 0, 999, 499, ["R" => 0, "G" => 0, "B" => 0]);

$scaleSettings = [
"XMargin" => 10,
"YMargin" => 10,
"Floating" => TRUE,
"GridR" => 200,
"GridG" => 200,
"GridB" => 200,
"DrawSubTicks" => TRUE,
"CycleBackground" => TRUE,
"LabelRotation" => 20,
//"GridTicks" => 50
//"Pos" => SCALE_POS_TOPBOTTOM
//"InnerTickWidth" => 20,
//"OuterTickWidth" => 20,
"Mode"=>SCALE_MODE_FLOATING 
];

$myPicture->setGraphArea(90,60,920,420);
$myPicture->drawScale($scaleSettings);
$myPicture->setFontProperties(["FontName" => "pf_arma_five.ttf", 
  "FontSize" => 11]);
$myPicture -> drawBarChart(array("DisplayOrientation"=>ORIENTATION_AUTO,"DisplayValues"=>TRUE,"DisplayColor"=>DISPLAY_AUTO,"Rounded"=>TRUE,"Surrounding"=>60,"Interleave"=>3));

$myPicture -> drawLegend(490,40,array("Style"=>LEGEND_NOBORDER,"Mode"=>LEGEND_HORIZONTAL));
$myPicture->Render("Test.png");

This is my code that produce an image file with bar chart drawn in it. The file name is "Test.png".

Can anyone help me draw bar chart without overlapping each others? I need to draw the bar chart without overlapping, and include it in PDF. Please refer to the link below for the current output from my code.

(https://www.dropbox.com/s/alqy4zsz70k1nqv/emobarTest.png?dl=0)