SUM和GROUP BY不起作用

Question

I encounter a worry in my request, it does not run correctly. Can you help me please ?

$ref_je = $pdo->query("SELECT SUM(Winner) AS Winn, SUM(Participation) AS Part, Reponse FROM tb_jeu_jeudi_reponses WHERE Pseudo='".$Pseudo."' GROUP BY Reponse");
while($data_je = $ref_je->fetch(PDO::FETCH_ASSOC)){
$Jeu_W = number_format($data_je["Winn"], 0, ',', ' ');
$Jeu_P = number_format($data_je["Part"], 0, ',', ' ');
}

The GROUP BY does not actually work. Do you have any idea please ?