Objective-See: entire site listed as unread on each post

I have noticed that for the following feed:


…each time there is a new post added, NewsBlur displays the entire feed’s list of 80 or so entries as if they were all suddenly new, instead of just the latest one.

Is it because the feed is missing some metadata? If yes, I’ll contact the author to fix it, but it seems to validate in a general feed validator, so I wasn’t sure.

In case it matters, I have the site set to Feed and Full display modes.