Laravel 6 Session and CSRF Cookies Not Being Set -- New Entry in Session DB for Each Page Load

I'm new to Laravel and have a Laravel 6 app where the session isn't acting as expected. It's causing a 419 - page expired error anytime I submit a form.

@csrf is included with every form, so that's not the issue.

Instead, what I'm seeing is that neither the Session cookie nor the XSRF-TOKEN cookie are being set in the browser. However, I do see the session creating a new ID in the database for every page load.

The sessions.php config file is the default one:

    'driver' => env('SESSION_DRIVER', 'file'),
    'expire_on_close' => false,
    'encrypt' => false,
    'files' => storage_path('framework/sessions'),
    'connection' => env('SESSION_CONNECTION', null),
    'table' => 'sessions',
    'store' => env('SESSION_STORE', null),
    'cookie' => env(
        'SESSION_COOKIE',
        Str::slug(env('APP_NAME', 'laravel'), '_').'_session'
    ),
    'path' => '/',
    'domain' => env('SESSION_DOMAIN', null),
    'secure' => env('SESSION_SECURE_COOKIE', false),
    'http_only' => true,
    'same_site' => null,

The VerifyCsrfToken.php Middleware file is the default one:

namespace App\Http\Middleware;

use Illuminate\Foundation\Http\Middleware\VerifyCsrfToken as Middleware;

class VerifyCsrfToken extends Middleware
{
    /**
     * Indicates whether the XSRF-TOKEN cookie should be set on the response.
     *
     * @var bool
     */
    protected $addHttpCookie = true;

    /**
     * The URIs that should be excluded from CSRF verification.
     *
     * @var array
     */
    protected $except = [
        //
    ];
}

The only session variables I've changed in the .env are:

SESSION_DRIVER=database
SESSION_COOKIE=lsession
SESSION_LIFETIME=43200

Other than confirming the @crsf token is included in every form, I've tried:

• testing in multiple browsers
• restarting my machine and trying again
• clearing the cache with php artisan cache:clear && php artisan config:cache
• switching back and forth between file and database session drivers

None of it works.

What else could be causing the session/csrf cookies to not be set?

Thanks so much in advance!