Cake PHP 2 associated model not saving

Question

I'm working in a legacy Cake PHP 2 project and have a model with some defined relationships. My request data I need to map as it's got other model names in it, so I'm doing this in my new model's beforeSave method.

When I try to save, it's saving the upper-most ApplicationVersionFive model just fine, but the related models such as ApplicationPaydayVersionFive just aren't saving and I have no idea why, it should be saving because my tables are configured:

My tables have a prefix in the database.php file.

• model: ApplicationVersionFive, table: tlp_application_version_fives
• model: ApplicationPaydayVersionFive, table: tlp_application_payday_version_fives

ApplicationVersionFive model

<?php
App::uses('HttpSocket', 'Network/Http', 'HttpResponse');

class ApplicationVersionFive extends AppModel
{
    public $name = 'ApplicationVersionFive';

    public $hasMany = array('RedirectVersionFive','ApplicationPromotionVersionFive', 'ApplicationApiLinkVersionFive');

    public $hasOne = array('ApplicationResponseVersionFive','ApplicationPaydayVersionFive','ApplicationInstallmentVersionFive','ApplicationSecuredVersionFive','ApplicationDebtmgmtVersionFive','ApplicationReclaimVersionFive', 'ApplicationPaydayIcicleHashVersionFive');

        /*
        ** Perform something before a model saves
        ** https://book.cakephp.org/2/en/models/callback-methods.html#beforesave
        */
        public function beforeSave($åoptions = array()) {
                $application = $this->data;

                $this->data = [
                        'ApplicationVersionFive' => $application['ApplicationVersionFive']['Application'],
                        'ApplicationPaydayVersionFive' => $application['ApplicationVersionFive']['ApplicationPayday'],
                        'ApplicationResponseVersionFive' => $application['ApplicationVersionFive']['ApplicationResponse'],
                        'ApplicationPaydayIcicleHashVersionFive' -> $application['ApplicationVersionFive']['ApplicationPaydayIcicleHash']
                ];

                // continue with save attempt
                return true;
        }
}

ApplicationPaydayVersionFive model

<?php
class ApplicationPaydayVersionFive extends AppModel
{
    public $name = 'ApplicationPaydayVersionFive';
    public $belongsTo = 'ApplicationVersionFive';
}

Called via:

$this->ApplicationVersionFive->saveAssociated($this->request->data, array('deep' => true));

What am I missing to get my linked models to save?

I should also be seeing the Application's model ID saved into the application_version_five_id column on my Payday model but I'm not: