Express-Session is undefined - node.js

Question

I am new to node.js and angular4 and am working on an application which required user authentication. I want to save the user role in a session in node.js and want to access that session in multiple routes. However, I am unable to get the role in other routes. I have checked many answers regarding the same but none have worked for me so far.
Scenario:
I have implemented Express-Session in app.js
const session = require('express-session');
const cookieParser = require('cookie-parser')
const app = express();
const port = 4000;
app.use(cors());
app.use(express.static(path.join(__dirname, 'public')));
app.use(bodyParser.json());
app.all('*',function(req, res, next){
res.header('Access-Control-Allow-Origin', 'http://localhost:4200');
res.header('Access-Control-Allow-Methods', 'PUT, GET, POST, DELETE, OPTIONS');
res.header('Access-Control-Allow-Headers', 'Content-Type');
res.header("Access-Control-Allow-Credentials", "true");
next();
});
app.use(cookieParser())
app.use(session({secret: "my secret", resave: false, saveUninitialized: true, cookie: { secure: !true }}));
I have a file named user.js which is being used for login user. After successful verification, user information is stored in a session.
res.json({
success: true,
token: 'JWT ' + token,
user: {
id: user[0].UserId,
FirstName: user[0].FirstName,
MiddleName: user[0].MiddleName,
LastName: user[0].LastName,
EmailID: user[0].EmailID,
PhoneNo: user[0].PhoneNo,
Role: user[0].Role,
DistrictId: user[0].DistrictId
},
});
req.session.userRole = user[0].Role;
req.session.save();
At this point, req.session.userRole has the user role.
However, when I use req.session.userRole in another route, eg: dept.js, it shows undefined.
Also, when I use Chrome app: Postman, it displays
Session {
cookie:
{ path: '/',
_expires: null,
originalMaxAge: null,
httpOnly: true,
secure: false },
userRole: 'ADMN' }
But when I run the application which is using Angular4, it just shows
Session {
cookie:
{ path: '/',
_expires: null,
originalMaxAge: null,
httpOnly: true,
secure: false }
PS: Node.js app is on port: 4000 and angular4 app is on 4200.
Thanks in Advance.