composer update hangs after configuring composer.json for asset-packagist

[anothersailor]

Please provide your composer.json if appropriate.

composer: 2.1.8 php 7.4

The insertion of the "repositories" hangs Composer when doing update, install or require. Although Composer passes validate & diagnose without problem.

Composer.json

{
    "name":"xxx",
    "description":"xxx",
    "license":"proprietary",
    "prefer-stable": true,
    "config": {
        "platform": {
            "php": "7.4"
        },
        "sort-packages": true
    },
    "require": {
        "ezyang/htmlpurifier": "^4.12",
        "html2text/html2text": "^4.2",
        "mobiledetect/mobiledetectlib": "^2.8",
        "monolog/monolog": "^2.0",
        "paypal/paypal-checkout-sdk": "^1.0",
        "phpmailer/phpmailer": "^6.0",
        "phpoffice/phpspreadsheet": "^1.16",
        "symfony/polyfill-mbstring": "^1.11",
        "symfony/yaml": "^4.4",
        "xemlock/htmlpurifier-html5": "^0.1.11"
    },
    "autoload": {
        "psr-4": {
            "vbClasses\\":"v5_php_modules/vbclasses/",
            "adminClasses\\":"v6_admin/v6_admin_php/adminClasses/"
        }
    },
    "require-dev": {
        "lyracom/rest-php-sdk": "^4.0",
        "phpunit/phpunit": "^8",
        "stripe/stripe-php": "^7.37"
    },
    "repositories": [
        {
            "type": "composer",
            "url": "https://asset-packagist.org"
        }
    ]
}