KnockoutJs Validation Async isValidating always true

Question

At a high level, I am trying to prevent form submission before async validation is complete and also ensure all is valid before submitting the form...

View Model Excerpt:

 ko.validation.rules['projectNameValidator'] = {
        async: true,
        validator: function (val, otherVal, callback) {
            if (self.ProjectId && self.ProjectId() > 0 && val === self.OriginalProjectName())
                return true;

            $.post("/ValidationBuild/IsProjectNameAvailable?name=" + val, function (data) {
                callback(data);
            });
        }
    };

ko.validation.registerExtenders();

  self.Name.extend({
        required: { message: 'Please Provide a project name' },
        projectNameValidator: { message: 'You have already used this project name, please use a unique project name' }
    });

 self.isValidating = ko.computed(function () {
        return self.Name.isValidating();
    });

    self.errors = ko.validation.group(self);

 self.formSubmit = saveData;

    return self;

  function saveData(data, event) {

        if (self.isValidating()) {
            setTimeout(function () {
                saveData(data, event);
            }, 50);
            return false;
        }

       // ko.validation check if valid
        if (self.errors().length > 0) {
            self.errors.showAllMessages(true);
            return;
        }

My problem is that self.isValidating is always true, I got this code from the answer to this StackOverflow question here: Knockout Validation async validators: Is this a bug or am I doing something wrong?

The only difference is that my saveData function is not part of the self or this viewModel like the answer example is but I don't think that matters.

Why is isValidating always true?