Insert is working local but not on server - php

Question

I use the same Code local and on the server.
While its working just fine local, there is no db-entry while running on the server.
While the INSERT statement is not working i can read and update the rows - so the connection should be fine.
Can somebody help me?
function setDataToParticipantTable($db_host, $db_password, $db_user, $db_name, $new_participant)
{
$db = new PDO('mysql:host=' . $db_host . ';dbname=' . $db_name, $db_user, $db_password);
$qry = "INSERT INTO " . "`TAEK_Subscriber19`" . " (`Vorname`, `Nachname`, `Email`, `Straße`, `Hausnummer`, `PLZ`, `Ort`, `Land`, `Turnusaerztevertreter`, `DO_VM_WS_1`, `DO_NM_WS_1`, `FR_VM_WS1_1`, `FR_VM_WS2_1`, `FR_NM_WS_1`, `Kongresseroeffnung`, `Kongressparty`, `Infotext`, `Hash`)
VALUES
(?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)";
$statement = $db->prepare($qry);
$statement->bindParam(1, $new_participant['Vorname']);
$statement->bindParam(2, $new_participant['Nachname']);
$statement->bindParam(3, $new_participant['Email']);
$statement->bindParam(4, $new_participant['Straße']);
$statement->bindParam(5, $new_participant['Hausnummer']);
$statement->bindParam(6, $new_participant['PLZ']);
$statement->bindParam(7, $new_participant['Ort']);
$statement->bindParam(8, $new_participant['Land']);
$statement->bindParam(9, $new_participant['Turnusaerztevertreter']);
$statement->bindParam(10, $new_participant['DO_VM_WS_1']);
$statement->bindParam(11, $new_participant['DO_NM_WS_1']);
$statement->bindParam(12, $new_participant['FR_VM_WS1_1']);
$statement->bindParam(13, $new_participant['FR_VM_WS2_1']);
$statement->bindParam(14, $new_participant['FR_NM_WS_1']);
$statement->bindParam(15, $new_participant['Kongresseroeffnung']);
$statement->bindParam(16, $new_participant['Kongressparty']);
$statement->bindParam(17, $new_participant['Infotext']);
$statement->bindParam(18, $new_participant['Hassh']);
$statement->execute();
$statement = null;
$db = null;
}