So after some testing, it definitely appears that Babble’s message channel doesn’t expect post replies via the API. The response to the /post.json is that it’s fine, 200 OK, with the body containing the details of the new post as expected.
I went ahead and installed a test Discourse env with Babble, and wired up a Hubot to communicate with. The Hubot reply posts will show up in the correct order, but only after a refresh. Before that, it’s like the bot isn’t saying anything. After refreshing the page, all of Hubot’s messages show up in the correct order.
Willing to work with you if I’m able to in order to get this resolved - I’m on the opposite side, where I’m not familiar with Babble’s message notification systems at all.