I am using version 3.8.4 of the plugin now.
I have a Newsletter dedicated page which is set up from “Subscription Steps” -> “Newsletter dedicated page”.
It has in its body the [newsletter_form] shortcode.
The exact code is:
[newsletter_form][newsletter_field name="email" label=""][/newsletter_form]
The problem is that when I try to subscribe through that page the form tag is ignored, because it is not closed, and I cannot subscribe.
You can check here: