@AltCode right, I think the issue here is that the posts themselves do not contain a backreference to the magazine they were posted to.
So for example, their latest post has addressed the following:
...
"to": [
"https://www.w3.org/ns/activitystreams#Public"
],
"cc": [
"https://flipboard.com/users/theverge/followers"
],
...
... note that the magazine itself is not included, and so when NodeBB receives the object, it does not know to slot the topic into the appropriate category.
cc @
[email protected] again about this one