Hi evilpcdiva,
thank You for Your interest!
I’ve checked the link, but that uses a different theme.
Basically with Jumadi, You have to go to Appearance-> Widgets menu and add navigation menu widget to left sidebar area.
After that at the customizer, go to Layout-> Sidebars section and You can setup the left sidebar.
I hope it helps! Have a nice day!
I did that, and it is still not displaying.
Here this might show you what I did:
https://imgur.com/a/JmaJGnU
I checked it, but unfortunately i couldn’t really find the solution.
It looks that the html structure broke somehow at the linked page. Maybe there is an extra closing div somewhere.
Please try to create a new page. I think the left sidebar will be available on a clean page like here: https://wpkoi.com/demos/jumadi/test/
After that try to add the content again and try to check when You loose the sidebar.
I hope it helps!