MySQL and PHP UTC time differs when in number format

I'm trying to make a login system, which in order to reset password or confirm the account I have a column with an 'expiration date', and for that expiration to work everywhere, I'm storing in UTC times. But I've come across something very weird. When I get the formatted UTC time from SQL and the formatted UTC time from PHP, both are the same. But when I get in numbers (I don't know what the real name of that format is) they differ exactly 7200 (which is the same as 2 hours difference). If anyone has any idea why is this happening? Thanks.

Here's the code I used to debug this:

<?php

$con = mysqli_connect('localhost', 'root', '', 'clients');

updateUserUTCTime($con, 3);
$user = getUserAssocArray($con, 3);

echo $user['date_utc'];
echo '<br>';
echo gmdate("Y-m-d H:i:s", time());
echo '<br>';
echo '<br>';
echo strtotime($user['date_utc']);
echo '<br>';
echo gmdate(time());
echo '<br>';
echo '____________';
echo '<br>';
echo strtotime($user['date_utc']) - gmdate(time());

function updateUserUTCTime($con, $id=1){
    $query = '
    update datetests 
    set date_utc = UTC_TIME()
    where id = '.$id.'
    ;';

    return mysqli_query($con, $query);
}

function getUserAssocArray($con, $id=1){
    $query = 'select * from datetests where id = '.$id.';';
    $result = mysqli_query($con, $query);
    $result = mysqli_fetch_assoc($result);
    return $result;
}

The output (at the time I've run the code) is:

2021-09-23 09:54:06
2021-09-23 09:54:06

1632383646
1632390846
____________
-7200

Note that when formatted they're the same, but when not, they differ 7200 units...

Ps: In the database, I'm using "DATETIME" type to store the UTC_TIME. I'm using the following functions to get UTC time in each language:

gmdate(time()) -> PHP

UTC_TIME() -> MySQL