Kadence Starter Template – Background Image Not Shown

I am using starter website https://startertemplatecloud.com/g02/
I tried to change the hero image of the original starter template of Kadence,

edit section > background > Background type: classic > select the image from my computer

the console of elementor showed what i changed, but when i updated it, it was blank on my website.
Then I made a new section, and added a background image. The same issue happened. The image looked okay in elementor’s console, but gone blank when I viewed it from my domain name.

This bothered me couple days. Hope I can get it solved here.

Thanks!