Laravel - Redirect::to or Redirect::back giving Tokenmismatchexception error?

Question

The following is happening, I have the login screen that does some checks, in case you do not pass any in my Controller I make a redirect for url login message with the error.

This is where the error, after the redirect with the message, and I try to login again is giving TokenMismatchException, just stops giving the error if I give a refresh on the page.

I’ve tried to use:

return Redirect::to('login');

and

return Redirect::back()->withInput();`

but to no avail.

Follows the codes:

View:

<form class="sign-in form-horizontal shadow rounded no-overflow" action="{{url('login/doLogin')}}" method="post">
    {{ csrf_field() }}
    <input type="text" class="form-control input-sm" placeholder="E-mail" name="username">
    <input type="password" class="form-control input-sm" placeholder="Senha" name="password">
    <button type="submit" class="btn btn-theme btn-lg btn-block no-margin rounded" id="login-btn">Entrar</button>
</form>

Controller:

<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;
use App\Models\User;
use Hash;
use Auth;
use Redirect;

class AuthController extends BaseController
{
    public $request = null;
    public function __construct(Request $request) {
        $this->request = $request;
    }
    public function doLogin(){
        $erro = "Erro ao logar";
        $requestedUser = $this->request->get('username');
        $requestedPassword = $this->request->get('password');
        $usuario = User::where('email', '=', $requestedUser)->first();
        if ($usuario) {
            if (Hash::check($requestedPassword, $usuario->password)) {
                if (!$usuario->userValidation) {
                    Auth::loginUsingId($usuario->id);
                    $this->toastrMessage("success", 'Logado com sucesso!');
                    return redirect('dashboard');
                }else{
                    $erro = "Acesse o seu e-mail para autenticar sua conta";
                }
            }else{
                $erro = "Senha incorreta";
            }
        }else{
            $erro = "Usuário não encontrado";
        }
        $this->toastrMessage("error", $erro);
        return Redirect::back()->withInput();
        // return Redirect::to('login');
    }
}

Remark¹: the version of Laravel is the 5.4 and have done projects with previous versions of Laravel and in none gave this error.

Observation²: As an interim measure I put the route that logs in to except of VerifyCsrfToken.