As Pon Thaeus mentioned his closed post, some posts don't show the comments in my timeline or group timeline. I guess this is some facebook malfunction, not because admins/moderators have done something in the post nor group.
In that case, you just CLICK the TIMESTAMP, then you can see the comments.
At least this works for my environment. And maybe help just a few people who have a similar situation to me.
I'm sorry to make this post since Pon's post had been closed already I cannot comment.
To admins/moderators, please delete or close this post If it's not appropriate.
(fyi: first photo is in my timeline, another with comments shows is opened directly by post link)