Why is the date passed but not displayed when passing an object to an instance ModelForm?

Question

Django

I am making a form for editing a database object, I want to make it so that when the page with the form is opened, it already contains data. I pass the required object to instance, but the values ​​​​are displayed only in the NumberField, Select and TextInput fields.
At the same time, in the debugger, when the form is initialized and in return, the values ​​\u200b\u200bof all fields are filled.
I suspect that this is a matter of bootstrap styles, or maybe not.
Who has already encountered such a problem, tell me what to do?

forms.py

class EditPriceForm(forms.ModelForm):
    class Meta:
        model = PriceList
        fields = [
            'dateBegin',
            'dateEnd',
            'cena',
            'flCancel',
            'idVallet'
        ]
        widgets = {
            'idVallet': forms.Select(attrs={
                'class': 'form-control'
            }),
            'dateBegin': forms.DateInput(attrs={
                'class': 'form-control',
                'type': 'date',
                'data-inputmask-alias': 'datetime',
                'data-inputmask-inputformat': 'dd/mm/yyyy',
                'data-mask': '',
            }),
            'dateEnd': forms.DateInput(attrs={
                'class': 'form-control',
                'type': 'date',
                'data-inputmask-alias': 'datetime',
                'data-inputmask-inputformat': 'dd/mm/yyyy',
                'data-mask': '',
            }),
        }

    def __init__(self, *args, **kwargs):
        super(EditPriceForm, self).__init__(*args, **kwargs)
        self.fields['cena'].widget = forms.NumberInput(attrs={'class': 'form-control'})
        self.fields['flCancel'].widget = forms.CheckboxInput(attrs={'class': 'form-control'})

views.py

@login_required
def EditPriceView(request, objId):
    if request.method == 'POST':
        form = EditPriceForm(request.POST)
        if form.is_valid():
            obj = PriceList.objects.get(id=objId)
            obj.cena = form.cleaned_data['cena']
            obj.dateBegin = form.cleaned_data['dateBegin']
            obj.dateEnd = form.cleaned_data['dateEnd']
            obj.flCancel = form.cleaned_data['flCancel']
            obj.idVallet = form.cleaned_data['idVallet']
            obj.summaRub = obj.cena + ((obj.cena/100)*2)
            obj.save()
            return redirect('/base/edit_nomenkl/'+str(obj.idNomenkl.id))
    if request.method == 'GET':
        form = EditPriceForm(instance=PriceList.objects.get(id=objId))
        return render(request, 'editPrice.html', {
            'form': form,
            'objId': objId
        })