Why is the application page (Django) not displaying information that the user is logged in?

Question

Django

Hello.
I ran into a problem:
I am performing authorization on the site being developed.
The template of any flatpages page shows that the user is logged in:

If you follow the link to the page with my application, you can see that the user is allegedly not authorized:

If you click on the login, then a message appears that the user is still authorized:

Both templates and the template the flatpages pages and my app's page template refer to the base template: The base template has the following code describing authorization information:
{% extends "base.html" %}

<div class="form">
            {% if user.is_staff %}
                <a href="{% url 'admin:index' %}">Панель администрирования</a>
                <br>
            {% endif %}

                {% if not user.is_authenticated %}
                    <a href="/accounts/login/">Вход</a>
                    |
                    <a href="/accounts/register/">Регистрация</a>
                {% endif %}

                {% if user.is_authenticated %}
                    <i class="icon-user"></i> <a href="/profiles/edit/">{{ user }}</a>
                    |
                    <a href="/accounts/logout/">Выход</a>
                {% endif %}

        </div>

Tell me, please, in which direction to dig in my application? Is CSRF to blame or do I need to look somewhere else for the problem?