MySQL Trigger Won't Fire After Insert From Wordpress Endpoint - mysql

Question

I want to delete all high scores except the top 10.
My query works fine as a query in PHPMysql, but when I try to use it in a trigger, it doesn't fire.
If anyone has a suggestion or needs additional information, please let me know. Thanks.
//The query
DELETE FROM ONEGameleaderboard WHERE _id Not IN
(SELECT * FROM (SELECT _id FROM ONEGameleaderboard ORDER BY Score DESC , Date ASC LIMIT 10) as t)
//The Trigger insert query
CREATE TRIGGER `ONEGameleaderboardTop10Limit` AFTER INSERT ON `ONEGameleaderboard`
FOR EACH ROW DELETE FROM ONEGameleaderboard WHERE _id Not IN
(SELECT * FROM (SELECT _id FROM ONEGameleaderboard ORDER BY Score DESC , Date ASC LIMIT 10) as t)
//The insert code form the WordPress endpoint (Which inserts the data just fine)
// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
$parameters = $request->get_json_params();
if($request['id'] == 1)
{
$sql = "INSERT INTO ONEGameleaderboard (Date, Name, Score) VALUES ('$parameters[Date]', '$parameters[Name]', '$parameters[Score]')";
}
elseif($request['id'] == 2)
{
$sql = "INSERT INTO TWOGameleaderboard (Date, Name, Score) VALUES ('$parameters[Date]', '$parameters[Name]', '$parameters[Score]')";
}
elseif($request['id'] == 3)
{
$sql = "INSERT INTO THREEGameleaderboard (Date, Name, Score) VALUES ('$parameters[Date]', '$parameters[Name]', '$parameters[Score]')";
}
else
{
$message = 'No Leaderboard Table for this Index';
return new WP_ERROR('no_data', $message, array('status' => 404));
}
if ($conn->query($sql) === TRUE) {
echo "New record created successfully";
} else {
echo "Error: " . $sql . "<br>" . $conn->error;
}
$conn->close();