I've php.format.rules.alignConstants enabled, but I found one case where this is not working.

<?php

declare(strict_types=1);

namespace ASDF;

const A2 = 1; // Not correctly formatted
const ABC2 = 2; // Not correctly formatted

class Test
{
    const A   = 1; // Correctly formatted
    const ABC = 2; // Correctly formatted
}

The two lines marked as not correctly formatted are not formatted because of the declared namespace.
Also if I nest the code in a namespace block it isn't formated.

It will only be formatted when removing the namespace.