Problems with Django Avatars

Question

I have a problem in my django app and when I edit a user my avatar photo is deleted and returns to the default one, I think the problem is in the views because it works correctly if I load the values from the django admin, If you could help me, I would appreciate it very much. This is the code:

Views:

@login_required
def editar_user(request): 
mensaje = ""
if request.method == "POST":
    extension_logued_user, _ = Avatar.objects.get_or_create(user=request.user)
    FormularioUser = NuestraEdicionUser(request.POST, request.FILES)

    if FormularioUser.is_valid(): 

        logued_user = request.user #intancia del Usuario
        logued_user.email = FormularioUser.cleaned_data['email']
        logued_user.first_name = FormularioUser.cleaned_data['first_name']
        logued_user.last_name = FormularioUser.cleaned_data['last_name']
        extension_logued_user.imagen = FormularioUser.cleaned_data['imagen']
        extension_logued_user.link = FormularioUser.cleaned_data['link']
        extension_logued_user.more_info = FormularioUser.cleaned_data['more_info']

        if FormularioUser.cleaned_data['password1'] != '' and `FormularioUser.cleaned_data['password1'] == FormularioUser.cleaned_data['password2']:`
            logued_user.set_password(FormularioUser.cleaned_data.get("password1"))
        else:
            mensaje = ""

        if extension_logued_user.imagen is None:
            pass
        
        logued_user.save()
        extension_logued_user.save()

        return render(request, "index/index.html", {"mensaje":mensaje}) 
    else:
        extension_logued_user, _ = Avatar.objects.get_or_create(user=request.user)
        return render(request, "EditUser.html", 

{"FormularioUser":FormularioUser,"mensaje":mensaje})

extension_logued_user, _ = Avatar.objects.get_or_create(user=request.user)
FormularioUser = NuestraEdicionUser(
    initial={
        'first_name': request.user.first_name,
        'last_name': request.user.last_name,
        'email': request.user.email,
        'imagen': extension_logued_user.imagen,
        'link': extension_logued_user.link,
        'more_info': extension_logued_user.more_info,
    }
)

return render(request, "EditUser.html", {"FormularioUser": FormularioUser, "mensaje":mensaje}) 

Template:

{% extends 'index/index.html' %}
{% load static %}

{% block Encabezado %}
<h1>Tu cuenta</h1>
{% endblock Encabezado %}

{% block PruebaTemplate %}

        {% if msj %}
            {{msj}}
        {% endif %}

        {% if request.user.avatar.imagen.url is not None%}
        <img src="{{request.user.avatar.imagen.url}}" alt="imagen de perfil" class="rounded-circle rounded mx-auto d-block" height="150" width="150"> <br>
        {% else %}
        <img src="{% static 'assets\img\fondo.png' %}" alt="imagen de perfil" class="rounded-circle rounded mx-auto d-block" height="150" width="150"> <br>
        {% endif %}
        
    
    <table>
        <h1 class="text-center">{{request.user.first_name}} {{request.user.last_name}}</h1> <br>
        <p> Email: {{request.user.email}}</p> 
        <p> Bio: {{request.user.avatar.more_info}}</p> 
        <a href="{{request.user.avatar.link}}">Pagina Web</a>  <br><br>
        <a href={% url 'EditarPerfil' %}>Editar Perfil</a>
    </table>

{% endblock PruebaTemplate %}