wishList = WishList.objects.get(pk=20)
matches = [val for val in Store.attribute_answers.all() if val in wishList.attribute_answers]

'ManyRelatedManager' object is not iterable

matches = [val for val in Store.attribute_answers.all() if val in WishList.attribute_answers.all()]

{% for room in study.room_choice.all %}
    {{ room }}
    {% empty %}
    empty list!
  {% endfor %}