Laravel 9 controller does not save in DB the json

Hello everyone.

I am having problems with storing data in postgresql database.

This is the migration.php

<?php

use Illuminate\Database\Migrations\Migration;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Support\Facades\Schema;

return new class extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('ciudadanos', function (Blueprint $table) {
            
            $table->id();
            $table->bigInteger('cuil')->unique();
            $table->string('nombre');
            $table->string('apellido');
            $table->string('email');
            $table->string('password');

            $table->timestamp('email_verified_at')->nullable();
            $table->boolean('confirmed')->default(0);
            $table->string('confirmation_code')->nullable();

            $table->rememberToken();
            $table->timestamps();

        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::dropIfExists('ciudadanos');
    }
};

The php artisan migrate runs ok!

This is the model:

<?php

namespace App\Models;

use Illuminate\Contracts\Auth\MustVerifyEmail;
use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;

class Ciudadano extends Model 
{
    protected $table = 'ciudadanos';

    protected $fillable =[ 
        'cuil',
        'nombre',
        'apellido',
        'email',
        'password',
    ];

    protected $hidden = [
        'password',
        'remember_token',
    ];

    protected $casts = [
        'email_verified_at' => 'datetime',
    ];

}

The api.php is this:

Route::post('ciudadano', 'App\Http\Controllers\CiudadanoController@store');

and this is the controller:

<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;

use App\Models\Ciudadano;


class CiudadanoController extends Controller
{
    /**
     * Display a listing of the resource.
     *
     * @return \Illuminate\Http\Response
     */
    public function index()
    {
        //
    }

    /**
     * Store a newly created resource in storage.
     *
     * @param  \Illuminate\Http\Request  $request
     * @return \Illuminate\Http\Response
     */
    public function store(Request $request)
    {


        dump($request);

        $this->validate($request, [
            'cuil'=>'required',
            'nombre'=>'required',
            'apellido'=>'required',
            'email'=>'required',
            'password'=>'required',
        ]);
    
        $ciudadano = Ciudadano::create($request->all());
        $ciudadano->save();
        return ("OK");
    }

    /**
     * Display the specified resource.
     *
     * @param  int  $id
     * @return \Illuminate\Http\Response
     */
    public function show($id)
    {
        //
    }

    /**
     * Update the specified resource in storage.
     *
     * @param  \Illuminate\Http\Request  $request
     * @param  int  $id
     * @return \Illuminate\Http\Response
     */
    public function update(Request $request, $id)
    {
        //
    }

    /**
     * Remove the specified resource from storage.
     *
     * @param  int  $id
     * @return \Illuminate\Http\Response
     */
    public function destroy($id)
    {
        //
    }
}

The problem is that it does not return "OK" and I can not debug it because console does not show anything.

If I set the return before $ciudadano = Ciudadano::create($request->all()); it returns "OK"

So the problem is with this line Ciudadano::create($request->all()) The client axios is this:

axios({
      method: 'post',
      url: 'http://127.0.0.1:8000/api/ciudadano',
      data: {"cuil":"xxxxx",nombre":"xxx", "apellido":"xxx", "email":"[email protected]", "password":"xxxxx"},
      headers: {
          "Content-Type": "application/json",
          'Access-Control-Allow-Origin' : '*',
          },
    }).then(function (response) { 
           console.log(response)
  });

What can be the problem here?