artisan tests pass when using in-mem DB, fail when using MySQL

I haven't figured out why this is happening, but I need to set up my tests and phpunit such that it uses a mysql database to seed and run database tests, instead of in memory / sqlite.

Originally, the tests worked perfectly with sqlite and everything passed, but I recently added a migration that uses some storedAs functions that sqlite can't handle (like DATEDIFF). So I need to use MySQL for the database tests now.

I made the changes to my .env, and my database.php config file, and my phpunit.xml file, but now every single test fails. If I ignore the mysql specific functions and go with the previous versions, they will still pass in-memory, but fail on MySQL.

I am using Laravel Herd, and DBNgin

Here is my phpunit.xml

<?xml version="1.0" encoding="UTF-8"?>
<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:noNamespaceSchemaLocation="./vendor/phpunit/phpunit/phpunit.xsd"
         bootstrap="vendor/autoload.php"
         colors="true"
>
    <testsuites>
        <testsuite name="Unit">
            <directory suffix="Test.php">./tests/Unit</directory>
        </testsuite>
        <testsuite name="Feature">
            <directory suffix="Test.php">./tests/Feature</directory>
        </testsuite>
    </testsuites>
    <coverage processUncoveredFiles="true">
        <include>
            <directory suffix=".php">./app</directory>
        </include>
    </coverage>
    <php>

        <env name="APP_ENV" value="testing"/>
        <env name="BCRYPT_ROUNDS" value="4"/>
        <env name="CACHE_DRIVER" value="array"/>
        <env name="DB_CONNECTION" value="testing"/>
        <env name="MAIL_MAILER" value="array"/>
        <env name="QUEUE_CONNECTION" value="sync"/>
        <env name="SESSION_DRIVER" value="array"/>
        <env name="TELESCOPE_ENABLED" value="false"/>
    </php>
</phpunit>

and here is my database.php config folder:

<?php

use Illuminate\Support\Str;

return [

    'default' => env('DB_CONNECTION', 'mysql'),

    'connections' => [

        'sqlite' => [
            'driver' => 'sqlite',
            'url' => env('DATABASE_URL'),
            'database' => env('DB_DATABASE', database_path('database.sqlite')),
            'prefix' => '',
            'foreign_key_constraints' => env('DB_FOREIGN_KEYS', true),
        ],

        'mysql' => [
            'driver' => 'mysql',
            'url' => env('DATABASE_URL'),
            'host' => env('DB_HOST', '127.0.0.1'),
            'port' => env('DB_PORT', '3306'),
            'database' => env('DB_DATABASE', 'forge'),
            'username' => env('DB_USERNAME', 'forge'),
            'password' => env('DB_PASSWORD', ''),
            'unix_socket' => env('DB_SOCKET', ''),
            'charset' => 'utf8mb4',
            'collation' => 'utf8mb4_unicode_ci',
            'prefix' => '',
            'prefix_indexes' => true,
            'strict' => true,
            'engine' => null,
            'options' => extension_loaded('pdo_mysql') ? array_filter([
                PDO::MYSQL_ATTR_SSL_CA => env('MYSQL_ATTR_SSL_CA'),
            ]) : [],
        ],

        'pgsql' => [
            'driver' => 'pgsql',
            'url' => env('DATABASE_URL'),
            'host' => env('DB_HOST', '127.0.0.1'),
            'port' => env('DB_PORT', '5432'),
            'database' => env('DB_DATABASE', 'forge'),
            'username' => env('DB_USERNAME', 'forge'),
            'password' => env('DB_PASSWORD', ''),
            'charset' => 'utf8',
            'prefix' => '',
            'prefix_indexes' => true,
            'search_path' => 'public',
            'sslmode' => 'prefer',
        ],

        'sqlsrv' => [
            'driver' => 'sqlsrv',
            'url' => env('DATABASE_URL'),
            'host' => env('DB_HOST', 'localhost'),
            'port' => env('DB_PORT', '1433'),
            'database' => env('DB_DATABASE', 'forge'),
            'username' => env('DB_USERNAME', 'forge'),
            'password' => env('DB_PASSWORD', ''),
            'charset' => 'utf8',
            'prefix' => '',
            'prefix_indexes' => true,
            // 'encrypt' => env('DB_ENCRYPT', 'yes'),
            // 'trust_server_certificate' => env('DB_TRUST_SERVER_CERTIFICATE', 'false'),
        ],
        'testing' => [
            'driver' => 'mysql',
            'host' => env('DB_TEST_HOST'),
            'port' => env('DB_TEST_PORT'),
            'database' => env('DB_TEST_DATABASE'),
            'username' => env('DB_TEST_USERNAME'),
            'password' => env('DB_TEST_PASSWORD'),
            'unix_socket' => env('DB_TEST_SOCKET'),
            'charset' => 'utf8mb4',
            'collation' => 'utf8mb4_unicode_ci',
            'prefix' => '',
            'prefix_indexes' => true,
            'strict' => true,
            'engine' => null,
            'options' => extension_loaded('pdo_mysql') ? array_filter([
                PDO::MYSQL_ATTR_SSL_CA => env('MYSQL_ATTR_SSL_CA'),
            ]) : [],
        ]

    ],

    'migrations' => 'migrations',

    'redis' => [

        'client' => env('REDIS_CLIENT', 'phpredis'),

        'options' => [
            'cluster' => env('REDIS_CLUSTER', 'redis'),
            'prefix' => env('REDIS_PREFIX', Str::slug(env('APP_NAME', 'laravel'), '_').'_database_'),
        ],

        'default' => [
            'url' => env('REDIS_URL'),
            'host' => env('REDIS_HOST', '127.0.0.1'),
            'username' => env('REDIS_USERNAME'),
            'password' => env('REDIS_PASSWORD'),
            'port' => env('REDIS_PORT', '6379'),
            'database' => env('REDIS_DB', '0'),
        ],

        'cache' => [
            'url' => env('REDIS_URL'),
            'host' => env('REDIS_HOST', '127.0.0.1'),
            'username' => env('REDIS_USERNAME'),
            'password' => env('REDIS_PASSWORD'),
            'port' => env('REDIS_PORT', '6379'),
            'database' => env('REDIS_CACHE_DB', '1'),
        ],

    ],

];

I know for a fact that the DB_TEST information is correct, and that the database exists and can be connected to. I can see it in TablePlus without issue, but when I run php artisan test, every single test fails.

Any ideas why?