nested inlines with SortableTabularInline

hi people, i had this code:

`
```python
class ReportSectionFieldInline(nested_admin.NestedTabularInline):
model = ReportSectionField
extra = 0
classes = ['collapse']

class ReportSectionInline(nested_admin.NestedTabularInline):
model = ReportSection
inlines = [ReportSectionFieldInline]
extra = 0
classes = ['secciones-informe']

class Media:
css = {
"all": ("admin/css/reportsection.css",)
}

class ReportAdmin(nested_admin.NestedModelAdmin):
list_display = ('id', 'description', 'type_report', 'modulo', 'active',)
search_fields = ('description', 'type_report',)
list_filter = ('type_report', 'active',)

inlines = [ReportSectionInline]
```

`

so, i want to drag and drop my ReportSectionFields . This is my new code:

`
```
class ReportSectionFieldInline(SortableTabularInline):
model = ReportSectionField
extra = 0
classes = ['collapse']

class ReportSectionInline(SortableTabularInline):
model = ReportSection
inlines = [ReportSectionFieldInline]
extra = 0
classes = ['secciones-informe']

class Media:
css = {
"all": ("admin/css/reportsection.css",)
}

class ReportAdmin(NonSortableParentAdmin):
list_display = ('id', 'description', 'type_report', 'modulo', 'active',)
search_fields = ('description', 'type_report',)
list_filter = ('type_report', 'active',)

inlines = [ReportSectionInline]

```
`

but now, i cant see in django-admin-panel the ReportSectionFieldInline i just see ReportAdmin and ReportSectionInline. How can i order this fields when i m working when 2 levels of nested objects?

before:

after: