Shortcode/widget not working

Hi,
I am having trouble using the shortcode [ez-toc] to show table of contents.
I am using Themeco PRO theme and their builder.
When I use the shortcode to show TOC, my page is completely blank without content, I can only see the header.
Test page:
https://www.projekti.grugru.hr/mozemorijeka/181-2/
I tried showing it with a widget, but it too doesn’t work.
I turned on the table of contents in page settings.

If I remove the shortcode, I can see TOC on top of the page like this:
https://prnt.sc/xljmfs

But I would like to use the shortcode or widget if possible, so I can change the position of TOC.
Can you help me with it?

Thanks.

The page I need help with: [log in to see the link]