Attached Docs Search Not found

I have attached the docs with the post. And with the help of short-code doc is displayed in the post. But when we will searched the attached docs with the search bar or with the help of plugin(facetious) then it will show “Nothing Found”.

Whats the problem please provide the solution for that. Or any recommendation will be appreciated

Thanks In advance

https://www.ads-software.com/extend/plugins/wp-better-attachments/