Hi Barry
You have disabled the overlay in funfact section from setting. So please first enable the overlay in funfact section.
You can Enable the overlay here Appearance >> Customize >> Frontpage Sections >> Funfact >> Overlay Enable/Disable
And also add the below CSS code in Additional CSS box
.theme-funfact-overlay {
background-color: rgba(0, 0, 0, 0.95) !important;
}
I hope it works for you.
Thanks
ThemeArile