Magazines from other instances not populating with posts

A couple lower popularity magazines I follow from lemmy.ml aren't populating with posts from those communities. Here is an example:

https://kbin.social/m/powerlifting@lemmy.ml
https://lemmy.ml/c/powerlifting

I made a test post in this community at the lemmy instance to see if it would show up on kbin, and it hasn't.

Is the syncing just lagging at the moment or is something broken?