[V5.6] Export Profile notification emails are not being sent

What happened?

We have an export profile notification created to send the report on a daily basis as a CSV to multiple emails (separated to new lines within the 'Emails to notify' field).

None of the email addresses listed receive the notification.

Other emails within Craft are sent without issue so we don't think this is a problem with the configuration of emails within Craft's settings or the email service provider.

Diagnostics Screenshot 2024-09-25 at 13 35 20

Errors and Stack Trace (if available)

2024-09-25 02:21:12 [web.ERROR] [TypeError] Cannot assign null to property Solspace\Freeform\Library\DataObjects\NotificationTemplate::$uid of type string {
    "trace":[
        "#0 /srv/app/htdocs/vendor/solspace/craft-freeform/packages/plugin/src/Bundles/Notifications/Export/ExportNotifications.php(86): Solspace\\Freeform\\Library\\DataObjects\\NotificationTemplate::fromRecord(Object(Solspace\\Freeform\\Records\\NotificationTemplateRecord))",
        "#1 [internal function]: Solspace\\Freeform\\Bundles\\Notifications\\Export\\ExportNotifications->handleNotifications(Object(yii\\base\\Event))",
        "#2 /srv/app/htdocs/vendor/yiisoft/yii2/base/Event.php(312): call_user_func(Array, Object(yii\\base\\Event))",
        "#3 /srv/app/htdocs/vendor/yiisoft/yii2/base/Component.php(650): yii\\base\\Event::trigger('craft\\\\web\\\\Appli...', 'afterRequest', Object(yii\\base\\Event))",
        "#4 /srv/app/htdocs/vendor/craftcms/cms/src/base/ApplicationTrait.php(544): yii\\base\\Component->trigger('afterRequest', Object(yii\\base\\Event))",
        "#5 /srv/app/htdocs/vendor/yiisoft/yii2/base/Application.php(387): craft\\web\\Application->trigger('afterRequest')",
        "#6 /srv/app/htdocs/web/index.php(12): yii\\base\\Application->run()",
        "#7 {main}"
    ],
    "memory":8514872,
    "exception":"[object] (TypeError(code: 0): Cannot assign null to property Solspace\\Freeform\\Library\\DataObjects\\NotificationTemplate::$uid of type string at /srv/app/htdocs/vendor/solspace/craft-freeform/packages/plugin/src/Library/DataObjects/NotificationTemplate.php:54)"
}

How can we reproduce this?

Create an export profile for any existing form
Create a daily export notification for that profile set to CSV type

Freeform Edition

Pro

Freeform Version

5.6.1

Craft Version

4.12.3

When did this issue start?

After upgrading from older Freeform version

Previous Freeform Version

4.1.22

solspace / craft-freeform