Multiple nested inline models save as new not working

[dbkv9]

Hi! I have next code (admin.py):

class ExampleForm(ModelForm):
    class Meta:
        model = Example
        exclude = []

    def is_multipart(self, *args, **kwargs):
        return True


class ExampleTabItemGalleryInline(GalleryFieldOverride, NestedTabularInline):
    model = ExampleTabItemGallery
    fk_name = 'tab_item'


class ExampleTabItemAdmin(GalleryFieldOverride, NestedStackedInline):
    model = ExampleTabItem
    fk_name = 'tab'
    inlines = [ExampleTabItemGalleryInline, ]


class ExampleTabAdmin(NestedStackedInline):
    model = ExampleTab
    inlines = [ExampleTabItemAdmin, ]
    fk_name = 'example'


class ExampleAdmin(NestedModelAdmin):
    inlines = [ExampleTabAdmin, ]
    form = ExampleForm
    
    save_as = True

When i save object with _saveasnew i have next trouble: saves only first inline model, that is -- ExampleTab and Example, but models nested into ExampleTab (ExampleTabItem, ExampleTabItemGallery) not saved... their fields is empty.