I am not sure how to interpret that, but I could imagine that publishing on your own account and later getting the story published on Universe Factory might have messed with the feed. For example if you look on the main page from UF
here you can see that
Cuban Missile War and
Golden Sails 1 were published on the same day - but
Cuban Missile War was published before
Golden Sails !, which might be the reason there was no "new" post in the feed.