jQuery: Form Submission - Multiple Event Handlers

Currently having some issues with jQuery Form Submissions in my project.

My project contains a general jQuery Code which prevents form double submissions (e.g. someone clicks the 'submit' button multiple times).

//prevent multiple form submissions
jQuery.fn.preventDoubleSubmission = function () {
    $(document).on('submit', this, function (e) {
        let $form = $(this);
        if ($form.data('submitted') === true) {
            e.preventDefault();
        } else {
            $form.data('submitted', true);
        }
    });
    return this;
};


$(function () {
    $('form').preventDoubleSubmission();
});

This code is included into every single page - so every form should be 'protected'.

For some specific forms I need to check some values before they are submitted - and show a confirm box, if some values are missing (e.g. Are you sure you want to submit this form without value X?)

Here's the code:

$(document).on('submit', 'form[name="article"]', function (e) {
    e.preventDefault();
    let form = this;
    let $form = $(form);
    let $category = $form.find('select#article_category'); //get category

    if ($category.length && !$category.val()) { //check if category is selected
        $.confirm({ //jquery confirm plugin
            title: Are you sure?,
            content: Value X is missing - continue?,
            buttons: {
                confirm: {
                    action: function () {
                        $form.off('submit');
                        form.submit();
                    }
                }
            }
        });
    } else {
        $form.off('submit');
        form.submit();
    }
});

So basically, if the user tries to submit the form, but the value X is missing, there will be a Yes/No Popup first - if the value exists, the form will be submitted right away.

Problem: When I want to submit the form, I call $form.off('submit'); to remove the event handler and submit afterwards with form.submit();. Sadly this also removes my preventDoubleSubmission event handler, which allows double submissions again.

Is there a way to fix my issue? Thanks

UPDATE 1: I am still struggling with this issue - it seems that $form.off('submit'); has no affect at all - which is weird because at first I had to implement it in order to be able to submit the form.

from jQuery: Form Submission - Multiple Event Handlers