delete table rows using jquery and ajax (foreach loop)

I'm trying to delete table rows base on the uncheck checkbox of my input fields like this,

So these are input fields,

Level 1<input value="1" class="checkbox" type="checkbox" name="rubric_chkbox[]" />
Level 2<input value="2" class="checkbox" type="checkbox" name="rubric_chkbox[]" />
Level 3<input value="3" class="checkbox" type="checkbox" name="rubric_chkbox[]" />

I'm using the next jquery code to get the data,

var uncheked = [];

$("input[name='rubric_chkbox[]']:not(:checked)").each(function()
{
    uncheked.push($(this).val()); 
});

console.log(uncheked);

Console.log return the array value ["3"] which is the unchecked checkbox value.

And this is my foreach loop on PHP,

if (isset($_POST['uncheked']) || isset($_POST['user_id']))
{
    $rubric_uncheck_value = $_POST['uncheked'];    
    $IDuser = $_POST['user_id'];

    foreach($rubric_uncheck_value as $rubric_uncheck)
    {
        $sql_check = "SELECT raw_selected_rubric
                      FROM rubric_selected
                      INNER JOIN cmat_composition ON rubric_selected.ID_cmat = cmat_composition.ID_cmat
                      WHERE rubric_selected.ID_users = '$IDuser'
                      AND raw_selected_rubric = '$rubric_uncheck'
                      AND rubric_selected.Saved = '1'";

        $result_check = mysqli_query($conn,$sql_check);

        if (mysqli_num_rows($result_check) > 0)
        {                
            $sql_raw = "DELETE raw_selected_rubric
                        FROM rubric_selected
                        WHERE raw_selected_rubric = '$rubric_uncheck'
                        AND ID_users = ''$IDuser'";

            mysqli_query($conn, $sql_raw);

            $sql_to_validated = "DELETE selected_rubric
                                 FROM validated_score
                                 WHERE selected_rubric = '$rubric_uncheck'
                                 AND ID_users = ''$IDuser'";

            mysqli_query($conn, $sql_to_validated);
        }
    }
}

But this does nothing. What can be the problem? Help please. Thank you.