Maybe I'm behind on this but I looked through all of the relevant posts I could find and can't get this working.
If I'm on my lemmy instance, I have figured out how to search for kbin magazines, but none of them populate/federate. For example, if I'm looking for /m/AskKbin I can search for https://kbin.social/m/AskKbin in my lemmy instance search bar, and it finds the community. But no posts are federated. This is the same for every community/magazine that I try and subscribe to from my lemmy instance