Check your login function, i had this problem and resolve with this in my AuthController:

public function Login(Request $request)
    {
        // If the class is using the ThrottlesLogins trait, we can automatically throttle
        // the login attempts for this application. We'll key this by the username and
        // the IP address of the client making these requests into this application.
        $throttles = $this->isUsingThrottlesLoginsTrait();

        if ($throttles && $lockedOut = $this->hasTooManyLoginAttempts($request)) {
            $this->fireLockoutEvent($request);

            return $this->sendLockoutResponse($request);
        }

        $credentials = ['nm_login' => $request->get('email'), 'password'=>$request->get('password')];

        if (Auth::guard($this->getGuard())->attempt($credentials, $request->has('remember'))) {
            return $this->handleUserWasAuthenticated($request, $throttles);
        }

        // If the login attempt was unsuccessful we will increment the number of attempts
        // to login and redirect the user back to the login form. Of course, when this
        // user surpasses their maximum number of attempts they will get locked out.
        if ($throttles && ! $lockedOut) {
            $this->incrementLoginAttempts($request);
        }

        return $this->sendFailedLoginResponse($request);
    }

I'm use custom login.

Sorry for my english, but i hope you understand

There was something wrong with my barryvdh/laravel-ide-helper. I had to start over with a fresh laravel install and copy/paste my code. Everything is fine now.

Thanks anyway.