Django table filter in ascending order not working

I am trying to filter an old list, but I noticed that when you reach 10, it does not filter it in ascending order anyone has an idea see photo

view.py

def anciennete(request):
    liste = Employe.objects.all().order_by('Anciennete')

page.html

<br>
<table class="table">
 <thead class="thead-light">
   <tr>
  <th scope="col">Ancienneté</th>
</tr>
</thead>
<tbody>

{% for i in liste %}
   <tr>
      <td>{{i.Anciennete}}</td>
   </tr>
{% endfor %}

table filter