Laravel update request validation not working on 9.x

I have create a validation request file on request folder. It working fine in new insert. But when i update, it's not working also i pass the unique $id but not working.

a. Resource controller update method

public function update(KlassNameRequest $request, $id)
{
    $validated = $request->validated();
    KlassName::where('id', $id)->update($validated);
}

b. Validation code

public function rules()
{
    return [
        'name'          => 'required|unique:klass_names|max:128,' . $this->id,
        'ref'           => 'required|unique:klass_names|numeric|between:1,999,' . $this->id,
        'seat_quota'    => 'required|numeric|between:1,9999',
        'division'      => 'required',
        'semester'      => 'required',
    ];
}

This message shows me when i update

I have solve my problem in this way -

a. Add extra input hidden field passing id for $request method. Because my route is resource group route -

<form action="{{ route('adm.kls.update', $kls->id) }}" method="post">
    @csrf
    @method('PUT')

    <input type="hidden" name="id" value="{{ $kls->id }}">
</form>

b. Some editing in validation code.

public function rules() {
  return [
    'name' => 'required|max:128|unique:klass_names,name,' . $this->id,
    'ref' => 'required|numeric|between:1,999|unique:klass_names,ref,' . $this->id,
    'seat_quota' => 'required|numeric|between:1,9999',
  ];
}

done.