If you visit https://lemmy.world/post/1181467?scrollToComments=true and check the post, the tiny comment icon under the post says that there are 5 comments. Checking the post however, you can see that there are only 3.
Is this some Lemmy bug, or does Lemmy shadow-remove comments like Reddit?
I see this a lot. Probably has to do with how the instances communicate. I deleted a post on Lemmy World and thought it was gone. Logged in on another instance and it was there. I could even reply if I wanted to and it was still getting upvotes. That's confusing.
Could be. I try to plan ahead to avoid deletion since on Lemmy the post just gets a deleted stamp on it (the text may or may not be deleted so I always edit out the comment before deleting) and your username remains, leaving people curious.
I noticed lots of posts were missing, like some communities were completely empty but in the sidebar it showed as having dozens of posts. I went to settings and made sure I had English and undetermined selected and suddenly they all appeared.
Not sure if that would be the same for comments but worth trying.