Troubleshooting flask error of storing and retreiving session cookies

Question

I am new to using flask for backend, and am facing an issue with storing sessions using memcached. I installed Memurai and connected to it and it was working fine. In my app. The login route apparently works fine and through thunderclient i can see a cookie being generated when user is logged in using correct credentials. However, error occurs when I visit the route /me, where I am constantly getting a 401 unauthorized error. Upon inspection using print commands (at line 44 and 45 of app.py), I can see that Session Data: <MemcachedSession {}> User ID: None , which prolly means the session is not storing any data. Here are my codes for app.py, config.py and models.py. I'd really appreciate if anyone helps me with this issue.

app.py:

from flask import Flask, request, jsonify, session
from flask_bcrypt import Bcrypt
from config import ApplicationConfig
from flask_session import Session
from models import db, User

app = Flask(__name__)
app.config.from_object(ApplicationConfig)

bcrypt = Bcrypt(app)
flask_session = Session(app)
db.init_app(app)

with app.app_context():
    db.create_all()
    
    
@app.route("/register", methods=["POST"])
def register_user():
    email = request.json["email"]
    password = request.json["password"]
    
    user_exists = User.query.filter_by(email=email).first() is not None
    
    if(user_exists):
        return jsonify({
            "error": "User already Exists"
        }), 409
    
    hashed_password = bcrypt.generate_password_hash(password).decode('utf-8')    
    new_user = User(email=email, password=hashed_password)    
    db.session.add(new_user)
    db.session.commit()
    
    return jsonify({
        "id":new_user.id,
        "email":new_user.email
    })

@app.route("/me")
def get_user():
    user_id = session.get("user_id")
    
    print("Session Data:", session)
    print("User ID:", user_id)
    
    if not user_id:
        return jsonify({"error":"Unauthorized"}), 401
    
    user = User.query.filter_by(id=user_id).first()
    return jsonify({
        "id":user.id,
        "email":user.email
    })

@app.route("/login", methods=["POST"])
def login_user():
    email = request.json["email"]
    password = request.json["password"]
    
    user = User.query.filter_by(email=email).first()
    
    if user is None:
        return jsonify({"error":"User Not Found"}), 401
    
    if not bcrypt.check_password_hash(user.password, password):
        return jsonify({"error":"Invalid Password"}), 401
    
    session["user_id"] = user.id
    
    return jsonify({
        "id": user.id,
        "email": user.email
    })


if __name__ == "__main__":
    app.run(debug=True)

config.py file:

from dotenv import load_dotenv
import os 

load_dotenv()

class ApplicationConfig:
    SECRET_KEY = os.environ["SECRET_KEY"]
    
    SQLALCHEMY_TRACK_MODIFICATIONS= False
    SQLALCHEMY_ECHO = True
    SQLALCHEMY_DATABASE_URI = r"sqlite:///./db.authapp"
    
    SESSION_TYPE= 'memcached'
    SESSION_PERMANENT = False
    SESSION_USER_SIGNER = True
    
    MEMCACHED_SERVER = ['127.0.0.1:6379']

models.py:

from flask_sqlalchemy import SQLAlchemy
from uuid import uuid4

db = SQLAlchemy()

def get_uuid():
    return str(uuid4())

class User(db.Model):
    __tablename__ = "users"
    id = db.Column(db.String(32), primary_key = True, unique = True, default= get_uuid)
    email= db.Column(db.String(345),unique=True)
    password= db.Column(db.Text, nullable = False)