how can i use absolute encoders with mcp23017?

[JuanFCulliganpy]

Hi, im really new on that, and i will craft by myselft this project, and i need help, i found this code for a midi interface. i craft the circuit and put all together, encoder, mcp23017 and arduino pro micro. when i did an i2c test it said me that is 0x20 adress its ok for me. but when i try on my daw and try to map any knob i can move the knob, after 1s(i guess) it back to the original position. as i said before prograaming is not my force, but i really like to do this project. here is my code:

#include <Wire.h>
#include <Control_Surface.h>
#include <AH/Hardware/MCP23017Encoders.hpp>

// Type for the MCP23017 encoders (translates encoder pulses to position)
using WireType = decltype(Wire); // The type of I²C driver to use
using EncoderPositionType = uint8_t; // The type for saving encoder positions
using MCPEncoderType = MCP23017Encoders<WireType, EncoderPositionType>;
using uint16 = uint16_t;

// Type for the MIDI encoders (translates position to MIDI messages)
struct PBMCPEncoder : GenericMIDIAbsoluteEncoder<MCPEncoderType::MCP23017Encoder, PitchBendSender<14>> {
PBMCPEncoder(MCPEncoderType::MCP23017Encoder enc, MIDIAddress address, int16_t multiplier = 600, uint8_t pulsesPerStep = 4)
: GenericMIDIAbsoluteEncoder(std::move(enc), address, multiplier, pulsesPerStep, {}) {}
};

USBMIDI_Interface midi;
//USBDebugMIDI_Interface midi;

// Create an object that manages the 8 encoders connected to the MCP23017.
MCPEncoderType encV {Wire, 0x20, 7};
// │ │ └─ Interrupt pin
// │ └────── Address offset
// └──────────── I²C interface

// Sends Pitch Bend messages
PBMCPEncoder pbencodersVOL[] {
{encV[0], MCU::VOLUME_1},
{encV[1], MCU::VOLUME_2},
{encV[2], MCU::VOLUME_3},
{encV[3], MCU::VOLUME_4},
{encV[4], MCU::VOLUME_5},
{encV[5], MCU::VOLUME_6},
{encV[6], MCU::VOLUME_7},
{encV[7], MCU::VOLUME_8},
};

// Create objects that receives Pitch Bend messages from DAW channels
PBValue enc_values[] = {
{MCU::VOLUME_1},
{MCU::VOLUME_2},
{MCU::VOLUME_3},
{MCU::VOLUME_4},
{MCU::VOLUME_5},
{MCU::VOLUME_6},
{MCU::VOLUME_7},
{MCU::VOLUME_8}
};

// Create some array to store encoder's position
uint16 prev_positions [8];
uint16 incoming_values [8];
uint16 new_positions [8];

void setup() {
Control_Surface.begin();
Wire.begin(); // Must be called before enc.begin()
Wire.setClock(800000);
encV.begin(); // Initialize the MCP23017
}

void loop() {
for (int i = 0; i < 8; i++) {
prev_positions[i] = pbencodersVOL[i].getValue();
}
static constexpr decltype(millis()) timeout = 1000;
static decltype(millis()) prev_enc_move_time = -timeout;

Control_Surface.loop();

for (int i = 0; i < 8; i++) {
new_positions[i] = pbencodersVOL[i].getValue();
incoming_values[i] = enc_values[i].getValue();
bool dirty = incoming_values[i] != new_positions[i];
// Keep track of when the user last moved the encoder.

if (new_positions[i] != prev_positions[i]) {
  prev_positions[i] = new_positions[i];
  prev_enc_move_time = millis();
}

// If the value last sent by the DAW is different from our local
// value, and if the user hasn't moved the encoder for a while,
// update our local encoder position value.
// Note: this assumes that the DAW always echoes back the value
//       it received.
else if (dirty && millis() - prev_enc_move_time >= timeout) {
  pbencodersVOL[i].setValue(incoming_values[i]);
  pbencodersVOL[i].forcedUpdate(); // send the new value to the DAW (optional)
}
encV.update(); 

}
}
i think its for the thing thats name PBMCPEncoder (i guess its pitchbend) but idk if it is.
If someone can helpme i will really apreciate that and of course when i finish my project, i share photos or videos.
thats for sure.
Thanks and keep safe.
Jose Franco