How to use Auth:user() in middleware properly?

I need to redirect to logout if user has role 'teacher'. I tried to do that with middleware but I dont know what is the problem here. It says

This page isn’t working 127.0.0.1 redirected you too many times.

, sometimes Auth:user() is null for no reason I guess.

Middleware:

public function handle($request, Closure $next)
    {
        if (Auth::user()->role == User::ROLE_TEACHER) {
            return redirect()->route('logout');
        }
        return $next($request);
    }

Kernel:

protected $routeMiddleware = [
       .....
        'noTeacher' => \App\Http\Middleware\RedirectIfTeacher::class,

    ];

HomeController:

$this->middleware('noTeacher', ['only' => 'index']);

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