What's up with "The magazine from the federated server may be incomplete. Browse more on the original instance."? Is this working as intended or is it a bug?

I've been seeing this for quite a bit, and thought it'd resolve itself once CloudFlare was taken off, but I'm still seeing it on many external communities from e.g. Lemmy. Not all posts or comments are visible from Kbin. Any idea on what's going on?

Edit, clarification: when I visit e.g., https://kbin.social/m/technology@beehaw.org the above mentioned sentence shows up, and I'm not able to see threads created even 13 hrs ago, like this one on the original instance https://beehaw.org/post/927935?scrollToComments=true. New content doesn't seem to be pushed to this instance at kbin.social. This is the issue I'm referring to.

Edit 2: This is probably the answer: https://kbin.social/m/kbinMeta/t/131241/What-s-up-with-The-magazine-from-the-federated-server-may#entry-comment-517045