Hello,
As per your query regarding the demo file of Selfgraphy, When we inspected on our side, it works fine. So, please make sure that you have imported the demo file properly.
For the proper clarification, here is the zip file of the demo from which you can import the demo content manually.
https://themepalace.com/instructions/themes/selfgraphy/#doc-demo-file-32
Here are the XML, dat and wie files. Import each file separately following the path :
Appearance > Import Demo Data.
You can go through the screenshot :
https://prnt.sc/qeodc4
Hope this helps.
If you have further queries, let us know.
Thank you.