POST on /posts returns null on moderated categories


When calling the /posts API endpoint on test_passed to submit a new topic in a moderated category, the following happens:

$ curl -X POST http://$(cat v2.6.0/ip)/posts -H "Accept: application/json" -H "Api-Key: $(cat v2.6.0/apikey)" -H "Api-Username: NONMEMBERNAME" -F raw='thanks is on the move message' -F title='a  title from the same user but different' -F category=15

However, when reverse engineering the call, it returns a JSON response that looks like this:

POST /posts with params raw=adn+very+intersteing+content&title=this+is+a+band+new+topic&unlist_topic=false&category=14&is_warning=false&archetype=regular&typing_duration_msecs=5500&composer_open_duration_msecs=16411&shared_draft=false&draft_key=new_topic&nested_post=true

{"action":"enqueued","success":true,"pending_count":7,"pending_post":{"id":8,"raw":"adn very intersteing content","created_at":"2020-11-20T23:13:52.015Z"}}

Any idea why the difference?