Django не позволяет вводить формы на неанглийских языках

В моей форме есть данные, которые я пытаюсь обозначить по-русски, например:

email = forms.CharField(label='ййй')

Проблема возникает, когда метка содержит только неанглийские символы, метка просто исчезает. Интересно, что когда метка содержит хотя бы один английский символ, метка появится, например:

email = forms.CharField(label='йййa')

Работает правильно.

Та же проблема возникает с атрибутами в параметре виджета.

email = forms.CharField(widget=forms.TextInput(attrs = {'placeholder': 'ййй'}))

Это HTML-код шаблона:

{% load widget_tweaks %}
  <h2>Sign up</h2>
<form method = "post">
  {% csrf_token %}

  {% for hidden_field in form.hidden_fields %}
    {{ hidden_field }}
  {% endfor %}

  {% if form.non_field_errors %}
    <div class = "alert alert-danger" role = "alert">
      {% for error in form.non_field_errors %}
        {{ error }}
      {% endfor %}
    </div>
  {% endif %}

  {% for field in form.visible_fields %}
    <div class = "form-group">
      {{ field.label_tag }}

      {% if form.is_bound %}
        {% if field.errors %}
          {% render_field field class = "form-control is-invalid" %}
          {% for error in field.errors %}
            <div class = "invalid-feedback">
              {{ error }}
            </div>
          {% endfor %}
        {% else %}
          {% render_field field class = "form-control is-valid" %}
        {% endif %}
      {% else %}
        {% if field.name == 'birth_date' %}
            {% render_field field class = "form-control date" id = "date" name = "date" %}
        {% else %}
            {% render_field field class = "form-control" %}
        {% endif %}
      {% endif %}

      {% if field.help_text %}
        <small class = "form-text text-muted">{{ field.help_text }}</small>
      {% endif %}
    </div>
  {% endfor %}

  <button type = "submit" class = "btn btn-primary">Submit</button>
</form>

Это выходной html-код:

  <h2>Sign up</h2>
<form method = "post">
  <input type='hidden' name='csrfmiddlewaretoken' value='Q2EvMWMCPrV597OQV8aqJwtC4X1zuSQI9oVdjeZtgzQUYTAYSp5v22cz2zfOZgwn' />



    <div class = "form-group">



            <input type = "text" name = "email" autofocus required class = "form-control" id = "id_email" />



    </div>

    <div class = "form-group">
      <label for = "id_id_num">Id number:</label>


            <input type = "text" name = "id_num" id = "id_id_num" required class = "form-control" maxlength = "9" />



    </div>

    <div class = "form-group">
      <label for = "id_password1">Password:</label>


            <input type = "password" name = "password1" required class = "form-control" id = "id_password1" />



        <small class = "form-text text-muted">&lt;ul&gt;&lt;li&gt;Your password can&amp;#39;t be too similar to your other personal information.&lt;/li&gt;&lt;li&gt;Your password must contain at least 8 characters.&lt;/li&gt;&lt;li&gt;Your password can&amp;#39;t be a commonly used password.&lt;/li&gt;&lt;li&gt;Your password can&amp;#39;t be entirely numeric.&lt;/li&gt;&lt;/ul&gt;</small>

    </div>

    <div class = "form-group">
      <label for = "id_password2">Password confirmation:</label>


            <input type = "password" name = "password2" required class = "form-control" id = "id_password2" />



        <small class = "form-text text-muted">Enter the same password as before, for verification.</small>

    </div>

    <div class = "form-group">
      <label for = "id_first_name">First name:</label>


            <input type = "text" name = "first_name" id = "id_first_name" required class = "form-control" maxlength = "30" />



    </div>

    <div class = "form-group">
      <label for = "id_last_name">Last name:</label>


            <input type = "text" name = "last_name" id = "id_last_name" required class = "form-control" maxlength = "30" />



    </div>

    <div class = "form-group">
      <label for = "id_birth_date">Birth date:</label>


            <input type = "text" name = "birth_date" required id = "date" name = "date" class = "form-control date" />



    </div>

  <button type = "submit" class = "btn btn-primary">Submit</button>
</form>