Validation error messages keep being loaded from system

Hi
I'm trying to translate the error messages from Validation service:

I've set in app/Config/App.php

Code:

public string $defaultLocale = 'es';

public array $supportedLocales = ['en', 'es'];

I've also created (as stated in userguide) the folder and file

Code:

app/Language/es/Validation.php

But the error messages keep being loaded from vendor/codeigniter4/framework/system/Language/en/Validation.php (I've confirmed this by changing strings there and trying again)

Am I ignoring anything else?

Enrique
https://beza.com.ar