Hello,
Postcode format of Paraguay has changed en 2018.
You can check here : https://en.wikipedia.org/wiki/List_of_postal_codes
It accepts 6 digits.
So the new regex in Formatter/PYFormatter.php is
^[0-9]{4}([0-9]{2})?$
Thanks
Romaric