Need advice regarding MuxShield II Arduino I/O and Analog Expander

Hi guys, MuxShield consist of 48 analog input that isolated with I/O1, I/O2 and I/O3 with 16 input each.

with I/O3 i can received my analog input fine without any issue.
The issue is if i tried to use two lane with is I/O2 and I/O3.

Here is the example code that is running fine.

/*This example shows how to use the Mux Shield for a combination of 
analog inputs, digital inputs, and digital outputs.
*/
#include <MuxShield.h>

//Initialize the Mux Shield
MuxShield muxShield;

void setup()
{

  muxShield.setMode(3,ANALOG_IN);          //set I/O 3 as analog input
  
  Serial.begin(19200);
}
//Arrays to store input values

void loop()
{
  
  //Read analog inputs on IO3
  const int analog1 = muxShield.analogReadMS(3,14);  //IO3, pin 14
  const int analog2 = muxShield.analogReadMS(3,15);  //IO1, pin 15
  
  //Print the results
  Serial.print("analog1: ");Serial.print(analog1);Serial.print('\t');
  Serial.print("analog2: ");Serial.print(analog2);Serial.println();
  
}

Output was great without any issue.

Here is the bad example:

/*This example shows how to use the Mux Shield for a combination of 
analog inputs, digital inputs, and digital outputs.
*/
#include <MuxShield.h>

//Initialize the Mux Shield
MuxShield muxShield;

void setup()
{

  muxShield.setMode(2,ANALOG_IN);
  muxShield.setMode(3,ANALOG_IN);          //set I/O 3 as analog input
  
  Serial.begin(19200);
}
//Arrays to store input values

void loop()
{
  
  //Read analog inputs on IO3
  const int analog1 = muxShield.analogReadMS(2,14);  //IO3, pin 14
  const int analog2 = muxShield.analogReadMS(3,15);  //IO1, pin 15
  
  //Print the results
  Serial.print("analog1: ");Serial.print(analog1);Serial.print('\t');
  Serial.print("analog2: ");Serial.print(analog2);Serial.println();
  
}

Output with both input connected to GND

image

i tried using I/O1 still same thing… is this related to the code or the hardware configuration? i havent touch any jumper on the bottom… it come still standart as it is.

Thank you!