Can't access instance method on mongoose model

Question

I defined an instance method on one of my schemas(userSchema) called correctPassword which should compare a candidate password to the hashed password stored in the DB, but it is not recognised on the User model.

user.schema.ts:

const userSchema = new mongoose.Schema<IUser>({
  name: {
    type: String,
    required: true,
    trim: true
  },
  password: {
    type: String,
    required: true,
    minlength: 8,
    select: false,
  },
  email: {
    type: String,
    required: true,
    trim: true,
    unique: true,
    lowercase: true,
    validate: validator.isEmail,
  },
  subscribers: {
    type: Number,
    default: 0,
  }
})

userSchema.pre('save', async function(next) {
  if (!this.isModified('password')) {
    return next()
  }
  this.password = await bcryptjs.hash(this.password, 12)
  next()
})

userSchema.methods.correctPassword = async function(candidatePassword, userPassword) {
  return await bcryptjs.compare(candidatePassword, userPassword)
};

export const User = mongoose.model<IUser>('User', userSchema)

When I try to call correctPassword on a User document the compiler says Property 'correctPassword' does not exist on type 'Document<unknown, {}, IUser> & IUser & { _id: ObjectId; }'.

The controller method:

public readonly login = async (req: Request, res: Response) => {
    const { email, password } = req.body
    if (!email || !password) {
      return res.status(400).json({ message: 'Body must contain email and password' })
    }
    
    const user = await User.findOne({ email }).select('+password');
  
    const passwordMatch = await user.correctPassword(password, user.password);
    if (!user || !passwordMatch) {
      return res.status(401).json({ message: 'Incorrect email or password' })
    }
    
    const token = this.signToken(user._id);
    return res.status(200).json({ token });
  }

I also tried defining the method directly in the schema options but faced the same issue.

I'm using Express 4.18.2, Mongoose 8.0.0