Hi,
I think I understand now.
The ‘global’ search is only searching the titles via the index table -> remember, I have changed that for a better performance (see my first reply), as there are over 35 000 posts in total, and even the titles generate over 300 000 keywords: https://i.imgur.com/pis982e.png
The restaurant search only looking within the restaurants, which is only ~400 posts, so the content search is also enabled.
I can try to re-create the index table to index the post contents as well, but the keyword count can go over 5+ million easily. It may affect the performance greatly. Do you want me to try that?