UPDATE Query not working - PHP/MySQL/bind_param - php

Question

It's a simple update code in a PHP function through a GET call from the front-end(Not sure if this matters), the code is converting a particular time zone value to unix time stamps -
$oldDate = null;
$newDate = null;
$ctr = 0;
$timeStamp = array();
$query= $this->userDatabaseConnection->stmt_init();
$query->prepare("SELECT Timestamp from Transaction INNER JOIN `Order` ON `Order`.TransactionId = Transaction.TransactionId");
$query->execute();
$query->bind_result($tID); //this holds the current time zone values
while($query->fetch()){
$oldDate = $tID;
array_push($timeStamp, $oldDate);
}
$query->close();
foreach($timeStamp as $row){
$newDate = strtotime($row);
$queryUpdate= $this->userDatabaseConnection->stmt_init();
$queryUpdate->prepare("UPDATE `Order` SET OrderDate=? WHERE TransactionId=?");
error_log("ERROR!",0);
$queryUpdate->bind_param('is', $unixTS, $oldTS);
$unixTS = $newDate;
$oldTS = $row;
$queryUpdate->execute();
$queryUpdate->close();
$ctr++;
}
if($ctr == 88){
return true;
}
else{
return false;
}
}
The $ctr variable is returning the total number of rows that need to be updated - which equals to the correct value and thus returns a true to my front end Angular controller.
I tried echo-ing the $newDate and $row values - they seem to be correct too.
But it just does not update my table. Can someone please help me figure out why? Am I missing something here? The error log does show the message in my Apache log - but I can't seem to figure out what's causing it.