LDAP Authentication not Working

I am currently using professional v22.4.11952 for Observium. I am unable to authenticate my Observium via my LDAP server (Windows Server 2019). When 'ldap' is applied, authentication doesn't work. php module required for Observium has already been installed.

Below is my config.php configuration:

// Authentication Model
$config['auth_mechanism'] = "mysql";    // default, other options: ldap, http-auth, please s>

$config['auth_ldap_binddn'] = "cn=Administrator,cn=Users,dc=domain01,dc=com";
$config['auth_ldap_bindpw'] = "xxxxxxx";

$config['auth_ldap_attr']['uid'] = "sAMAccountName";
$config['auth_ldap_attr']['uidNumber'] = "objectSid";
$config['auth_ldap_attr']['cn'] = "name";
$config['auth_ldap_objectclass'] = "user";

$config['auth_ldap_version'] = 3;
$config['auth_ldap_server'] = "server01.domain01.com";
$config['auth_ldap_port'] = 389;
$config['auth_ldap_starttls'] = FALSE;

$config['auth_ldap_prefix'] = "cn=";
$config['auth_ldap_suffix'] = ",ou=mvc,DC=domain01,DC=com";
$config['auth_ldap_group'] = array("cn=gtgroup,ou=mvc,DC=domain01,DC=com");
$config['auth_ldap_groupbase'] = "cn=gtgroup,ou=mvc,DC=domain01,DC=com";

$config['auth_ldap_groupmembertype'] = "nondn";
$config['auth_ldap_groupmemberattr'] = "member";

unset($config['auth_ldap_groups']);
$config['auth_ldap_groups']['mvc']['level'] = 10;

Is there something I missing out on my LDAP configuration? Please advice. Thanks