So, I see some comment, post view from my instance is missing comparing to view from that original instance. Which prevent me to interact (like, comment)
As a user, how to tell the instance to update missing content ?
Copying the original link in the search bar sometimes work.
Keep in mind that different content or users might be removed or banned on different instances.
it is feel like from original instance, a post is so popular having ~20 comment. But from my instance it have 0 comment.
I've noticed this as well but only with lemmy.world content. I think it has something to due with the overall size of the instance.
There's been a bug in lemmy that makes posts really slow. Check the version your instance is running, i believe most of the bug was worked out in BE: 0.19.3. That info is at the bottom of the page
If you're instance is running that or newer, the admin might need to reboot some of the services or the server.
You can put the home instance URL of a post or comment into search on your instance to force federation.
This will then allow you to comment/reply to that thing.
If you're not on lemmy world, but the poster/community that you're looking at is on lemmy.world, that could be your answer. Due to the way lemmy currently processes federated content, lemmy.world is big enough that many other instances aren't able to process lemmy.world messages as fast as it produces them, meaning that the smaller instances fall ever further behind lemmy.world
Your instance is a few millions actions behind LW:
Probably something to bring up to your admin
If it's due to defederation, no. If it's due to defederation, your only option is to choose a new home instance.
One thing you might have done is have deselected the language (including "unspecified") on your home instance. That would hide comments and posts tagged with that language. I did that inadvertently. If that's it, just turn it back on.
Or you could have blocked the user or instance on your home instance, and if so, you can unblock them.