If you're missing replies on posts, check your language settings (details in post body)
Please make sure you have "undetermined" selected in your list of spoken languages in your lemmy settings in addition to any other languages you speak.
Most lemmy content does not come through with a language tag, and you need to have undermined selected as an option to see that content.
You'll know if it's not done right because you'll see a post that says it has 5 replies or something, but then when you open it, you can't see (m)any replies
I'll also make another reply to this without using a language tag. If you can see that, your settings are correct