magento2: unable to remove block from Magento 2 home page

I am working on the Magento 2 website that someone developed before me. The website has Ultimate Theme.
I am trying to remove a block with a slider at the top of the home page. In the Ultime guide, that block is referred to as a static "preface" block (found below the navigation bar and just above the page content). The actual block has the CSS class "slideshow-wrapper-additional", but on the admin page under Content -> Blocks there is no block with that name.

So should i remove it using admin panel or direct connection via ftp / ssh?

I have Magento 2.2.9 and Ultimate Theme 2.