Hi Paula,
I checked your 'Blog' menu item and it seems the menu item links to the category called 'Succession Blog', this is the issue. When we access other categories, they will regard the category 'Succession Blog' as their parent menu item. This causes conflict, thus making those categories not able to load.
Actually, single categories should be using the EasyBlog frontpage menu item as their parent menu item, not another category.
My suggestion is to change the Blog menu item type to (Posts)Frontpage. That way, all categories can use EB frontpage as their parent menu item making EasyBlog menu structure more organized and eliminate potential menu item conflicts.
Hope this help.