This repo documents a potential issue in Django 2.2.
Either via tests:
pip install django pytest pytest-django cd fktest DJANGO_SETTINGS_MODULE=fktest.settings pytest
Or via the Python REPL:
python manage.py makemigrations python manage.py migrate python manage.py shell from fk.models import Author, Book a = Author.objects.create(name='Bill') b1 = Book.objects.create(title='Sonnets', state='deleted') b2 = Book.objects.create(title='Hamlet') b1.authors.add(a) b2.authors.add(a) a.books.count() # 2 a.books.all().count() # 1