Getting a lot of 404s when updating via composer

What does your repositories section in your composer.json say?
You're trying to download these packages from the wrong repository it seems.
I expected them to come from https://asset-packagist.org/

e.g.

    "repositories": [
        {
            "type": "composer",
            "url": "https://packages.drupal.org/8"
        },
        {
            "type": "composer",
            "url": "https://asset-packagist.org"
        }
    ],

Hi Ronald,

That's exactly what i have. I have attached a screenshot