flaky federation between kbin.social and lemmy.sdf.org, trying to determine where the issue lies

I have an account on lemmy.sdf.org and I am subscribed to a magazine here on kbin.social (m/mma)

however, federation of posts and comments is extremely flaky or non-existent and I'm not sure if the issue is on the kbin side, the lemmy side, or both?

anyone have some insight into where this breakdown might be occurring?

for example, here are some screenshots of m/mma on kbin and lemmy

notice how most kbin content has not federated over to the lemmy side on lemmy.sdf.org

I also tried to comment on a kbin post from lemmy and as of 15 minutes later the comment has not appeared on the kbin thread

kbin sorted by 'new'
kbin

lemmy sorted by 'new' (notice how lemmy is missing most threads and also missing most comments from the Jamahal Hill thread)
lemmy

EDIT: I should mention that lemmy.sdf.org appears to be on 0.18.2 so they are pretty good at keeping it up-to-date