Values won't be sent to databank

I have created a form, where I can add a new book. However, after I push the create button nothing happens, it just refreshes. Could you please help me with this problem?

Controller:

<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;
use App\Book;
use App\Language;
use App\Genre;
use App\Author;
use App\Publisher;

class BookController extends Controller
{ 
    public function index(Request $request)
    {
        $books = Book::with(['language', 'authors', 'publishers', 'genres'])->get();

        return view('books/index', compact('books'));
    }

    public function create()
    {
        $languages = Language::all();
        $genres = Genre::all();
        $authors = Author::all();
        $publishers = Publisher::all();
        
        return view('books/create', compact('languages','genres','authors','publishers'));
    }
     
    public function store(Request $request)
    {
        $validatedData = $request->validate([
            'title' => 'required|max:255',
            'authors' => 'array|min:1',
	        'authors.*' => 'exists:authors,id',
            'year' => 'required|numeric|max:2500',
            'publishers' => 'array|min:1',
	        'publishers.*' => 'exists:publishers,id',
            'genres' => 'array|min:1',
            'genres.*' => 'exists:genres,id',
            'language_id' => 'required',
            'isbn' => 'required|numeric|max:9999999999999',
            'pages' => 'required|numeric',
        ]);

        $book = Book::create($validatedData);
        $book->authors()->attach(request('authors'));
        $book->genres()->attach(request('genres'));
        $book->publishers()->attach(request('publishers'));


        return redirect('books')->with('success', 'Buch wurde erfolgreich hinzugefügt!');
    }

    public function show($id)
    {
        $book = Book::findOrFail($id);
        $languages = Language::all();
        $genres = Genre::all();
        $authors = Author::all();
        $publishers = Publisher::all();


        return view('books/show', compact('book', 'languages', 'genres','authors','publishers'));
    }

    public function edit($id)
    {
        $book = Book::findOrFail($id);
        $languages = Language::all();
        $genres = Genre::all();
        $authors = Author::all();
        $publishers = Publisher::all();

        return view('books/edit', compact('book', 'languages', 'genres','authors','publishers'));
    }

    public function update(Request $request, $id)
    {
        $book=Book::findorFail($id);
        $validatedData = $request->validate([
            'title' => 'required|max:255',
            'authors' => 'exists:authors,id',
            'year' => 'required|numeric|max:2500',
            'publishers' => 'exists:publishers,id',
            'genres' => 'exists:genres,id',
            'language_id' => 'required',
            'isbn' => 'required|numeric|max:9999999999999',
            'pages' => 'required|numeric',
        ]);
        $validatedData =$request->all();
        $book->fill($validatedData)->save();
        $book->authors()->attach(request('authors'));
        $book->genres()->attach(request('genres'));
        $book->publishers()->attach(request('publishers'));

        return redirect('books')->with('success', 'Buch wurde erfolgreich bearbeitet!');
    }

    public function destroy($id)
    {
        $book = Book::findOrFail($id);
        $book->delete();

        return redirect('books')->with('success', 'Buch wurde erfolgreich entfernt!');
    }

    public function search(Request $request)
{
    $validatedData =$request->validate([
        'book_search' => 'min:3',
    ]);

    $search = $request->get('book_search');
    $books = Book::with(['language', 'authors', 'publishers', 'genres'])->where('title','like','%' .$search. '%')->get();
    
    return view('books/index', compact('books'));
    
}
}

create.blade.php

@extends('layout')


@section('title')
<title>Neues Buch hinzufügen</title>
@section('stylesheets')
<script src="http://code.jquery.com/jquery-3.4.1.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/js/select2.min.js"></script>
<link href="https://cdn.jsdelivr.net/npm/[email protected]/dist/css/select2.min.css" rel="stylesheet" />


@endsection
@section('content')
<style>
    .uper {
        margin-top: 40px;
    }
</style>
<div class="card uper">
    <div class="card-header">
        Neues Buch hinzufügen
    </div>
    <div class="card-body">
        <form method="post" action="{{ route('books.store') }}">
            
        <div class="form-group">
                @csrf
                <label for="title">Titel:</label>
                <input type="text" class="form-control" name="title" value="{{ old('title')}}" />
                @error('title')
                <div class="alert alert-danger">{{ $message }}</div>
                @enderror
            </div>

            <div class="form-group">
                <label for="authors">Author(en):</label>
                <select name="authors[]" multiple class="form-control select2-multi <!-- @error('authors') is-invalid @enderror -->">
                    @foreach ($authors as $author)
                    <option value="{{ $author->id }}" {{ in_array($author->id, old('authors') ?? []) ? 'selected' : '' }}>
                        {{ $author->name }}
                    </option>
                    @endforeach
                </select>
                @error('authors')
                <div class="alert alert-danger">{{ $message }}</div>
                @enderror
            </div>

            <div class="form-group">
                <label for="year">Jahr:</label>
                <input type="text" class="form-control" name="year" value="{{ old('year')}}" />
                @error('year')
                <div class="alert alert-danger">{{ $message }}</div>
                @enderror
            </div>

            <div class="form-group">
                <label for="publishers">Verlag(e):</label>
                <select name="publishers[]" multiple class="form-control select2-multi <!-- @error('publishers') is-invalid @enderror -->">
                    @foreach ($publishers as $publisher)
                    <option value="{{ $publisher->id }}" {{ in_array($publisher->id, old('publishers') ?? []) ? 'selected' : '' }}>
                        {{ $publisher->name }}
                    </option>
                    @endforeach
                </select>
                @error('publishers')
                <div class="alert alert-danger">{{ $message }}</div>
                @enderror
            </div>

            <div class="form-group">
                <label for="genres">Genre(s):
                @foreach($genres as $genre)
                <input type="checkbox" name="genres[{{$genre->id}}]"@if(array_key_exists($genre->id, old('genres', []))) checked @endif > {{$genre->name}}
                @endforeach
            </label>
                </select>
                @error('genre_id')
                <div class="alert alert-danger">{{ $message }}</div>
                @enderror
            </div>

            <div class="form-group">
                <label for="language_id">Sprache:</label>
                <select name="language_id" class="form-control @error('language_id') is-invalid @enderror">
                    <option value="{{ old('language_id')}}">-- {{ __('Spache auswählen') }} --</option>
                    @foreach ($languages as $language)
                    @if (old('language_id') == $language->id)
                    <option value="{{ $language->id }}" selected>{{ $language->name }}</option>
                    @else
                    <option value="{{ $language->id }}">{{ $language->name }}</option>
                    @endif
                    @endforeach
                </select>
                @error('language_id')
                <div class="alert alert-danger">{{ $message }}</div>
                @enderror
            </div>

            <div class="form-group">
                <label for="isbn">ISBN:</label>
                <input type="text" class="form-control" name="isbn" value="{{ old('isbn')}}" />
                @error('isbn')
                <div class="alert alert-danger">{{ $message }}</div>
                @enderror
            </div>

            <div class="form-group">
                <label for="pages">Seitenzahl:</label>
                <input type="text" class="form-control" name="pages" value="{{ old('pages')}}" />
                @error('pages')
                <div class="alert alert-danger">{{ $message }}</div>
                @enderror
            </div>

            <button type="submit" class="btn btn-primary">Hinzufügen</button>
        </form>
    </div>
</div>
<script type="text/javascript">
        $(".select2-multi").select2();
	</script>

@endsection

Model:

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class Book extends Model
{
    protected $fillable = ['title', 'year', 'language_id', 'isbn', 'pages', 'authors','publisher','genres'];

public function publishers(){
     return $this->belongsToMany(Publisher::class);
}

public function authors(){
   return $this->belongsToMany(Author::class);
} 

public function genres(){
     return $this->belongsToMany(Genre::class);
}

public function language(){
    return $this->belongsTo(Language::class);
}

public function readers()
    {
        return $this
            ->belongsToMany(Reader::class, 'book_reader')
            ->using(Checkout::class)
            ->withPivot(['id', 'returndate', 'maxreturndate']);
    }


}