Some Sub-items Not Visible in Menu

I have three sub-items in a given menu category (“Garden Sites”); only one (“Buffalo,” which I just created) is appearing in the menu. The other two, which were previously working before I eliminated a parent category and reassigned them to “Garden Sites,” are now not appearing. I have tried removing and adding them to the menu, as well as removing the parent category and reassigning that. Nothing has caused them to reappear.

https://www.imaginecommunitygardens.org/