Fail to retrieve Post data with Laravel - laravel

Question

I try to learn Laravel (v.9) from scratch but fail to do a simple basic task:
I just want to send "post_var" by POST request and display the var.
My form (blade template):
<form action="/post_and_show" method="POST">
#csrf
#method('post')
<input type="text" name="post_var">
<input type="submit" value="send">
</form>
My Route (in web.php) with some dd() i tried to find the problem
Route::post('/post_and_show', function (Request $request) {
dd($request->method()); // returns GET ?? !!
// chrome debugger network tab show clearly its a POST request...
dd($request->all()); // returns empty Array
dd($request->post_var); // returns null
dd($request->getContent()); // returns string but i want param only
// "_token=yBBYpQ303a1tSiGtQF6zFCF6p6S7qadVfHMk4W7Q&_method=post&post_var=12345"
});
What am i doing wrong here?
Tried several methods i found in the documentation but non worked so far.
EDIT: I removed "#method('post')"
Btw.: My initial version that did not work either had no "#method('post')". I added it later on in the hope it might help...
<form action="/post_and_show" method="POST">
#csrf
<input type="text" name="post_var">
<input type="submit" value="send">
</form>
But have still the same problems:
Route::post('/post_and_show', function (Request $request) {
dd($request->method()); // returns GET ?? !! but chrome says its a post request
dd($request->post_var); // returns null
dd($request->get('post_var'));// returns null
dd($request->getContent()); // returns complete body and header in one string
dd($request->all()); // return empty Array
});
EDIT 2:
Googleing i found "createFromGlobals":
use Illuminate\HTTP\Request; // just added this to show which class i use here...
use Illuminate\Support\Facades\Route;
Route::post('/post_and_show', function () {
dd(Request::createFromGlobals()->get('post_var')); // returning expected value
});
This works for me, but i can't find this method in documentation. Sorry, i am new to laravel and even php, so this seems all completely crazy to me.. ;-)
EDIT 3:
If i use a simple Controller it works too...
Controller:
namespace App\Http\Controllers;
use Illuminate\Http\Request;
class FormController extends Controller
{
public function show(Request $request)
{
dd($request->post_var); // returns expected value...
}
}
Route:
Route::post('post_and_show', [FormController::class, 'show']);
So only in case i use the $request immediatly in the callback it does not work as expected. ( Either by design or bug??)