Thank you @Vero.
I believe that I've exactly followed every step.
Still, I cannot get the folders or files via Alfred.
Just as you've said, it's indeed a Spotlight / macOS Metadata issue. I also hope we can have some solution to figure it out.
@Stephen_C Thank you for your reply. I've tried, but I failed.
I could not get any files which list on the desktop, even with spotlight.
It's wired, and it makes me crazy. You can see that all files are there, but you can get nothing when you're searching with alfred.