Querys wont work on MSSQL Server 2016 with PDO connection over sqlserv

Question

currently im working for a "fun" project and im stuck at a point. I created a MSSQL Server 2016 on Windows Server 2016 R2 and added a database and also some tabels. Now i want to select data from my database with PHP and there via PDO. But i wont get any output with my selections. I always end up in the "Sorry, we are missing your account!" part...

Note: The connection is working and i also can use INSERT INTO and UPDATE and so on.

Here is my PHP Script:

<?php
try {
    $conn = new PDO("sqlsrv:Server=(local);Database=SomeDatabase", "SomeUser", "SomePassword");
    $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

    $user = explode('\\', strtolower($_SERVER['AUTH_USER'])); //Split AUTH_USER into domain and username String

    /*Check if user in Database*/
    $sql = "SELECT * FROM account WHERE domain=:dom AND username=:user;";

    $preparedQuery = $conn->prepare($sql);

    if(!$preparedQuery->execute([':dom' => $user[0], ':user' => $user[1]])){
        die('There was an error running the query.');
    }

    if ($preparedQuery->rowCount() == 1) {
        echo "Willkommen, ".$user[1];
    } else {
        echo "Sorry, we are missing your account!<BR>Please contact our administrator.";
    }

} catch(Exception $e) {
    die(print_r($e->getMessage()));
}

?>

Here is my Profiler Output if i call the Script: http://i.epvpimg.com/WYfCeab.png

Always my rowCount() gives me -1 as output but thats not true... It also isnt working when i try "SELECT * FROM account;" with no parms... (Also i changed == 1 to >= 1 when i was trying the SELECT *)

Does anybody know why i wont be abel to get some outputs? Because the connection is working and i can use querys like INSERT. (The user also got the permissions for the select, i already checked it)