Thank you page after form submission

Hi everyone,

I need help. I have a form that after submission displays the thank you page, just as is described in the Learn site.
I want the page to display the form contents that were just submitted (and are correctly sent via email). However, that does not happen and I can’t figure out what might be causing this.

Any help is welcomed. Thank you in advance.

current contents of “formdata.html.twig”

{% extends 'partials/base.html.twig' %}

{% if form is null %}
    {% set form = grav.session.getFlashObject('form') %}
{% endif  %}

{% block content %}
    <div class="container">
        <div class="col-md-6 col-12 formdata-thankyou">
            {{ content|raw }}

            {% if form %}
                {% include 'partials/form-messages.html.twig' %}

                <p>{{ 'PLUGIN_FORM.DATA_SUMMARY'|t }}</p>

                {% include "forms/data.html.twig" %}

            {% else %}
                <div class="notices warning yellow"><p>{{ 'PLUGIN_FORM.NO_FORM_DATA'|t }}</p></div>
            {% endif %}
{% endblock %}