Café

here is another tip that should be useful while browsing "all".

remember to make use of this colored star icon. it brings you to the instance a post originated from (so you won't see it on local posts).

now, for the explanation of why that is important…the best I can do is by comparison, so if it doesn't make sense to you, do ask for clarifications.

here it goes…federation on lemmy is like email, sometimes messages don't get through due to the server being unreachable. lemmy will try to resend those affected comments, but it can't keep doing so forever.

so if the server remains unreachable for too long, there will be comments that are not synchronized to it. besides that, if you are the first person to subscribe to a remote community, only the original posts are retrieved, new comments will come in as they are posted across the fediverse, but not old ones.

I guess (haven't really looked for a proof of it) what is guaranteed is you'll see nested comments in which users from your instance have participated in, but for others you'll have to keep in mind the possibility of there being comments that could be "missing".

which brings us to that colored icon, it is available for both original posts and comments. but I think it is more important for posts, if you click on it and see a comment on the source instance that has not synchronized properly to your instance, you can copy the url of the chain/link icon, switch back to your instance, and search for it.

that should force synchronize that particular comment (and its parent comments) over to your instance, and with that you'll be able to reply to a comment that was originally "missing". I hope this helps and isn't overly confusing. for more information, you can have a look at the lemmy documentation.