UserFailedLogin error, but login is successful

[thomasboel]

PHP version: 7.4.13 vgrem/phpSPO version: latest from composer require vgrem/php-spo

I have tested a very minimal setup using the following code snippet

use Office365\SharePoint\ClientContext;
use Office365\Runtime\Utilities\RequestOptions;
use Office365\Runtime\Utilities\UserCredentials;

$username = '[email protected]';
$password = 'userpassword';
$endpoint = "https://tenant.sharepoint.com";

$queryUrl = $endpoint . "/sites/SITE/_api/web/lists/GetByTitle('ListName')/Items";

$request = new RequestOptions($queryUrl);
$authCtx = new AuthenticationContext($endpoint);

$authCtx->acquireTokenForUser($username, $password);

$ctx = new ClientContext($queryUrl, $authCtx);
$resp = $ctx->executeQueryDirect($request);

Data is retrieved and everything seems fine, but in the Azure Active Directory logs, a UserFailedLogin error occurs, and since I fetch quite often on the production application, the errors logs keep spamming the customer's log system.

Is this a known bug for vgrem/phpSPO, anyone else with the same issue?

This could very well be the fault of some configuration on SharePoint or Azure Active Directory, any help is much appreciated.