laravel validation error and flash session not working

I have installed laravel 5.8 project via :

composer create-project --prefer-dist laravel/laravel project2"5.8.*"

after I run:

php artisan make:auth

I can visit 127.0.0.1:8000/login but when I enter wrong email or password I get redirected back without error messages.

here is my rutes:

 Domain | Method   | URI                    | Name                 | Action                                                                 | Middleware   |
+--------+----------+------------------------+----------------------+------------------------------------------------------------------------+--------------+
|        | GET|HEAD | /                      |                      | Closure                                                                | web          |
|        | GET|HEAD | api/user               |                      | Closure                                                                | api,auth:api |
|        | POST     | complete-registration  | completeRegistration | App\Http\Controllers\auth\RegisterController@completeRegistration      | web,guest    |
|        | GET|HEAD | home                   | home                 | App\Http\Controllers\HomeController@index                              | web          |
|        | GET|HEAD | login                  | login                | App\Http\Controllers\Auth\LoginController@showLoginForm                | web          |
|        | POST     | login                  |                      | App\Http\Controllers\Auth\LoginController@login                        | web          |
|        | POST     | logout                 | logout               | App\Http\Controllers\Auth\LoginController@logout                       | web          |
|        | POST     | password/email         | password.email       | App\Http\Controllers\Auth\ForgotPasswordController@sendResetLinkEmail  | web,guest    |
|        | GET|HEAD | password/reset         | password.request     | App\Http\Controllers\Auth\ForgotPasswordController@showLinkRequestForm | web,guest    |
|        | POST     | password/reset         | password.update      | App\Http\Controllers\Auth\ResetPasswordController@reset                | web,guest    |
|        | GET|HEAD | password/reset/{token} | password.reset       | App\Http\Controllers\Auth\ResetPasswordController@showResetForm        | web,guest    |
|        | GET|HEAD | register               | register             | App\Http\Controllers\Auth\RegisterController@showRegistrationForm      | web,guest    |
|        | POST     | register               |                      | App\Http\Controllers\Auth\RegisterController@register                  | web,guest    |
|        | GET|HEAD | verify-code            | verify_code          | App\Http\Controllers\auth\RegisterController@show_verify_code          | web,guest    |

I tried:

php artisan clear:cache
php artisan config:cache
php artisan view:clear
php artisan route:clear

also tried to delete vendor folder and then:

composer install install --no-cache

but nothing worked, why laravel is not returning errors?

via Chebli Mohamed