INMP441 audio data not correctly saved by flask server, why?

Question

So this is my Esp32 code I'm using the esp32 wroom 32 wifi and bluetooth module:

#include <WiFi.h>
#include <HTTPClient.h>
#include <driver/i2s.h>
#include <ArduinoJson.h>
#include <Base64.h>
// WiFi credentials
const char* ssid     = "SSID";
const char* password = "PASSWORD";

// Server details
const char* serverName = "FLASK URL/route";

// INMP441 I2S pin assignment
#define I2S_WS 25
#define I2S_SD 33
#define I2S_SCK 32

// Button and LED pin assignment
#define BUTTON_PIN 12
#define LED_PIN 13

unsigned long ledOnTime = 0;
bool recording = false;

void setup() {
  Serial.begin(115200);

  // Connect to WiFi
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Connecting to WiFi...");
  }
  Serial.println("Connected to WiFi");
 if(WiFi.status() == WL_CONNECTED) {
    HTTPClient http;
    http.begin(serverName);
    int httpResponseCode = http.GET();
    Serial.println(httpResponseCode);
    if(httpResponseCode!=405){
      while(httpResponseCode!=405){
         int httpResponseCode = http.GET();
            Serial.println(httpResponseCode);
            if(httpResponseCode==405){
              break;
            }
      };
      http.end();
    };
    

  }
  i2s_config_t i2s_config = {
    .mode = (i2s_mode_t)(I2S_MODE_MASTER | I2S_MODE_RX | I2S_MODE_PDM),
    .sample_rate =  44100,
    .bits_per_sample = I2S_BITS_PER_SAMPLE_16BIT,
    .channel_format = I2S_CHANNEL_FMT_ALL_LEFT,
    .communication_format = I2S_COMM_FORMAT_I2S,
    .intr_alloc_flags = ESP_INTR_FLAG_LEVEL1,
    .dma_buf_count = 2,
    .dma_buf_len = 1024
  };

  i2s_pin_config_t pin_config;
  pin_config.bck_io_num = I2S_SCK;
  pin_config.ws_io_num = I2S_WS;
  pin_config.data_out_num = -1;
  pin_config.data_in_num = I2S_SD;

  i2s_driver_install(I2S_NUM_0, &i2s_config, 0, NULL);
  i2s_set_pin(I2S_NUM_0, &pin_config);
  i2s_set_clk(I2S_NUM_0, 44100, I2S_BITS_PER_SAMPLE_16BIT, I2S_CHANNEL_MONO);

  // Set the button as input
  pinMode(BUTTON_PIN, INPUT_PULLUP);

  // Set the LED as output
  pinMode(LED_PIN, OUTPUT);
}

void loop() {
  // Check if the button is pressed
   if (digitalRead(BUTTON_PIN) == 0 && !recording) {
    digitalWrite(LED_PIN, HIGH); // Turn on the LED
    ledOnTime = millis();
    recording = true;
  }
  if (recording) {
     // Turn on the LED

    uint16_t i2s_read_buff[1024];
    size_t bytes_read;

    // Record for 10 seconds or until the button is released
     for(int i = 0; i < 10 * 44100 / sizeof(i2s_read_buff); i++) {
    i2s_read(I2S_NUM_0, i2s_read_buff, sizeof(i2s_read_buff), &bytes_read, portMAX_DELAY);

    // Send audio data to Flask app
    if(WiFi.status()== WL_CONNECTED){
      HTTPClient http;
      http.begin(serverName);
      http.addHeader("Content-Type", "application/json");

      // Base64 encode the audio data
      String base64Audio = base64::encode((uint8_t*)i2s_read_buff, bytes_read);

      // Create a JSON object with the audio data
      StaticJsonDocument<200> doc;
      doc["audio"] = base64Audio;
      String json;
      serializeJson(doc, json);

      // Send the JSON object in the POST request
      int httpResponseCode = http.POST(json);
      http.end();
    }
    else{
      Serial.println("WiFi Disconnected");
    }
  }
  if (millis() - ledOnTime >= 10000) {
      digitalWrite(LED_PIN, LOW); // Turn off the LED
       if(WiFi.status() == WL_CONNECTED){
  HTTPClient http;
  http.begin( "flask URL /save");
  int httpResponseCode = http.POST("");
  http.end();
}
      recording = false;
    }
   

  }
 
}

There is a simple btn connected to the esp32, when the btn is pushed an led turns on signaling that the flask server is starting to receive audio data from the inmp441 mic. I did enter my SSID and PASSWORD as well as the correct server URL. I'm also sending a get request just to set initial flask connection as my esp32 takes like 10 minutes to establish an initial connection to the flask server

currently this is my server code:

from flask import Flask, request
from pydub import AudioSegment
import io
import base64

app = Flask(__name__)

# List to store all incoming audio segments
audio_segments = []

@app.route('/endpoint', methods=['POST'])
def handle_audio():
    data = request.get_json()
    base64_audio = data['audio']
    audio_data = base64.b64decode(base64_audio)

    # Create an AudioSegment from the raw data
    incoming_audio = AudioSegment.from_raw(io.BytesIO(audio_data), sample_width=2, frame_rate=44100, channels=1)

    # Add the incoming audio to the list of segments
    audio_segments.append(incoming_audio)

    return 'Audio data received!'

@app.route('/save', methods=['POST'])
def save_audio():
    # Concatenate all audio segments
    combined_audio = sum(audio_segments)

    # Export as FLAC
    combined_audio.export("PATH/Desktop/output.flac", format="flac")

    return 'Audio data saved as FLAC file!'

if __name__ == '__main__':
    app.run(host='0.0.0.0', port=5000)

yes I know its not the best way to save an audio file with another post request but its temporary. My problem is that the audio data I essentially save is simply noise and that even though the recording is 10 seconds only 4 seconds is saved in the file. The audio data is received as separate chunks. After all the chunks have been received it saves the file

What I want to do is simply record voice audio for 10 seconds and save it as an audio file through a flask server. Can anyone please help... Thanks