Comments from years ago are top. Most recent comments do not appear.
It looks fine on our end. Can you share the author and ticker you are trying to filter on?
For instance, J. Mintzmyer 7/13/18 article on TGP. If I look at his page, click comments, and click TGP in the left side menu (shows 611 comments for that ticker), the most recent comment is shown to be 1/19/18. He made many comments on that 7/13/18 article.
Another is example is Matthew Utesch's 7/16/18 article on ABR. Same process shows the most recent comment to be 10/12/17 - but his most recent comment on the article page is 7/18/18.
Customer support service by UserEcho