categories not showing the listings when clicked

Hello,

I am using child theme directory of parent heme classifieds. Now, I have added a category clock on home page as can be seen here https://solardirectory.in/ . There are listings already present in those categories but when we click on a particular category, instead of showing listing it shows the message “This is somewhat embarrassing, isn’t it?
It seems we can’t find what you’re looking for. Perhaps searching can help.”
(snapshot attached)
When same category is selected in advanced search, it shows the relevant listings. (snapshot attached)
Please help as this is a main segment of website and its not functioning.

Thanks
Nirat