Why doesn't sorting work in django templates?

Question

Django

There are two classes:

class TreeNode(MPTTModel):
    contract_date = models.DateField(null=False, blank=False)
    parent = TreeForeignKey('self', verbose_name='родитель', null=True, blank=True, related_name='children')
    
    class Meta:
        ordering = ['contract_date']

class ClientToCompanyPayment(models.Model):
    total = models.PositiveIntegerField(verbose_name='Сумма платежа', blank=False, null=False)
    date = models.DateField(verbose_name='Дата платежа', blank=False)
    client = models.ForeignKey(TreeNode, verbose_name='Участник', related_name="filterpayments")

    class Meta:
        abstract = True


class CashPayment(ClientToCompanyPayment):

    class Meta:
        ordering = ['date']

For some reason sorting by Meta.ordering in

{% for payment in user.treenode.filterpayments.all %} (возвращает объекты типа CashPayment)

works, but does not work. What can be wrong?
{% for child1 in user.treenode.children.all %}

Answer 1

I remember that in MPTTModel it was required to specify a certain ordering value . It seems by tree_id and lft .
I wouldn't bother; you can make the procedure ordered_children in the model, which displays the necessary elements and in the right order, and call it from the template.