Hey, so I know some of you may be new or may have never wrapped your head around what any of this federation stuff means regarding Lemmy, so I aim to keep this simple while linking to more detailed posts for those interested in more technical background at the bottom.
The short of it is, your posts and comments to communities hosted here on Lemmy World or elsewhere, or comments to posts from others on Lemmy World from elsewhere, may be taking awhile to be visible to others outside of Lemmy World. In other words, if you've posted to a community on say, Lemmy.nz or Aussie.zone (for the most dramatic examples), you may not have seen any responses until much later because it took that long for them to process & receive them.
This is a known technical issue with the present Lemmy version that is currently being discussed and worked on. As I understand it, this is in large part due to the concentration of activity on Lemmy World, while some other delays are related to geographic factors, both smashing together for one gnarly snag with the Lemmy software.
So what does this mean for you? Well, if you would like more timely communications with a variety of other Lemmy sites' communities, you may consider moving from Lemmy World to another Lemmy site.
Lemmy World is up to date with Lemmy, meaning you can export your settings (including user/community/instance blocks and community subs) and import on other up to date Lemmy sites. This tends to be easiest via the web interface so far as I'm aware.
Alternatively you may remain with an awareness of why you may not have seen many replies/comments to some of your comments/posts on other sites' communities, or suddenly see notifications for replies/comments to "old" comments/posts. People may only now be seeing them some time later.
Lemmy Federation Issue Discussion
Other Related Discussions:
Lemmy NZ Update on Lemmy World Federation Issues
Why do comments from lemmy.world users not appear until 4 days later?
Reddthat Update and Notice on Lemmy World Federation Issues
dbzer0 Federation Mishaps Postmortem
Communities Moving From Lemmy World Related to Delays
QuiteInteresting community notice
CasualConversations community discussion/notice
p.s. if I've misunderstood the issues in some way, please correct me in the comments. I've tried to avoid citing additional configuration hiccups besides dbzer0's (e.g. I think Sopuli's recent delays were something like this), such as World's own from around a month ago to keep focus on the underlying Lemmy issue.