This happens for me on a small number of posts, and is generally repeatable, even when the website shows comments.
For instance, running on lemmy.world, GetPost(id: 290602) tells me the post exists and has 7 comments, as does https://lemmy.world/post/290602
But GetComments(postId: 290602) returns an empty list.
If I run against the original post on ‘programming.dev’, GetComments(postId: 99912) does show me the comments, but I don’t think I’m supposed to be second guessing the federating logic :-)
Has anyone seen anything similar or can confirm they see this same behaviour for this post?
I was running into this. I’ve noticed that some instances seem to have limits to how many comments you can fetch at a time, especially when there is no “limit” or “page” set. Setting “limit” or “page” or a parent id seems to avoid it. The limits for each server might be under getSite(), but if those limits are related to this issue specifically, haven’t tested it