Hoping this is an easy one. I have created my first article, using SP Page Builder Pro and there is a section at the top which I can identify what it is so I can get rid of it. Here is a screen shot, using the Position Preview, its the space in the in the red outline.
https://drive.google.com/file/d/19hHyyc7WMaxil7Bc0XDaN_9LmZDAJaZC/view?usp=sharing
I am using the Joomla article as opposed to a SP PB Page as I want to try to use JFilters for filtering and I beleive that it looks at the Articles though I haven't spent much time with it. Also your demo site has the blog using artticle so though that would be the best choice
Cheers
p.s. I have updated the image, the Social Icons in the red circle, bottom right also shouldn't be there. I have all social icons disabled where I found them, obviously missing a place, and they only show up in the Article