I regularly see posts from Technology@kbin.social without delays, with sort order on "new". Maybe the sort order influences this? I've also heard that posting to kbin from lemmy or vice versa helps increasing traffic between them, but I don't know if or how much that's true.
interesting, there is something odd going on with mma@kbin.social at least
here is what both platforms look like when sorting by 'new'
notice how Lemmy is missing most recent posts, and Lemmy is missing 4/5 comments from the Jamahal Hill post (Lemmy is also missing 5/7 comments from the Francis Ngannou post)
I don't know if you're moderating any communities/magazines, but have you tried posting from a lemmy account on the kbin instance moderated by you, and then making your lemmy account a mod there? Or vice versa.