datetime input old value with livewire

I use a dateTime-local input but it does not show the existing date when I want to update.

<div class="col-span-4">
     <label class="block font-medium text-sm text-gray-700" for="form.start_date">
           {{ __('start date') }}
     </label>
     <input wire:model.defer="form.start_date" type="datetime-local" id="form.start_date" name="form.start_date" class="border-gray-300 py-3 px-4 rounded-md shadow-sm mt-1 block w-full">
</div> 

Other inputs show old values due to wire:model.defer but why this one not working? How to solve it?