Mongoose unresolved method or function with @types/mongoose installed

If I require a mongoose model like so: `const User = require('./user')`

WebStorm can't resolved those method like, `find()` or `save()` but the code obviously works. And `const {User} = require('./user')` all the method are resolved but the app breaks. Only when I do something like this, declaring a variable first, it works:

const express = require('express');
const router = express.Router();
const argon2 = require('argon2');
const jwt = require('jsonwebtoken');

let User;
User = require('./user');

router.get('/', async function(req, res, next) {
  const users = await User.find({});
  res.status(200).json(users);
});

router.post('/new', async (req, res, next) => {
  const hash = await argon2.hash(req.body.password);
  let user = new User({
    email: req.body.email,
    password: hash
  });
  await user.save();
  res.status(201).json(user);
});

router.post('/login', async (req, res, next) => {
  const email = req.body.email;
  const user = await User.findOne({ email: email });

  if (user) {
    try {
      if (await argon2.verify(user.password, req.body.password)) {
        const token = jwt.sign(
          { id: user._id, email: user.email },
          `${process.env.JWT}`,
          { expiresIn: '1h' }
        );
        res.status(200).json({ token: token });
      } else {
        res.status(401).json({ message: 'Incorrect credentials' });
      }
    } catch (e) {
      console.log(e);
    }
  }
});

module.exports = router;

And I have @types for express and mongoose.
Why is that? What am I missing?