Why is the download of an excel file forced?

I am trying to show an excel file, but this one instead of showing what it does is download it at once.

Thus I try to show the file

public function ari(){

     $file = storage_path() . '\app\excel\formulario ORIGINAL ARI.xlsx';
     $headers = ['Content-Type' => 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet'];

     return response()->file($file, $headers);
}

However if I deal with a file pdf I have no problem.

public function cardAval(){

    $file = storage_path() . '\app\pdf\carta-aval.pdf';
    $headers = ['Content-Type' => 'application/pdf'];

    return response()->file($file, $headers);

}

So the browser shows me the file and does not force the download as in the file excel , What am I wrong?