If SerializerMethodResourceRelatedField is called with many=True and creates child field it misses call to bind() which would complete setting the relation between parent field and child field.

In effect it breaks the pattern that on every DRF field you can always go up the tree towards the root using parent attribute.

That part of ManyRelatedField.init() is missing:

class ManyRelatedField:
    ...
    def __init__(self, child_relation=None, *args, **kwargs):
        self.child_relation = child_relation
        ...
        self.child_relation.bind(field_name='', parent=self)

I am aware that there are some issues related to SerializerMethodResourceRelatedField already reported in #639, but since this bug is completely independent thing, I report it as separate issue.