Hi,

Your config is wrong.

You're mixed with config from 2 mega menu types: mega menu columns & category mega menu.

Seem you're trying to create a category mega menu, please do following steps to fixed this:

1/ Go to Appearance > Menus > on menu item "Blog" > remove all child menu items of this menu item - check this image

2/ On this screen, edit menu item "Blog" > remove class "megamenu" from this menu item.

A note for you: I see you're using plugin A3 LazyLoad - this plugin conflict with this theme and make all your images can't display. Please delete this plugin - and you don't need this plugin because this theme already has this feature from itself.

Best Regards,

PenciDesign