Finder content search only displays files after being opened

In Finder, when searching a file contain a certain word, for example, "Floor" in any format file (pdf, word, excel, or even the text file created by the TextEdit.

The Finder only shows those files I have click and opened and read before.

Attached the screenshots. There is file named "Floor1" with text content "Floor1".

But In Finder search, there is not file in result.

After I click and open the text file, search again. This file will be shown in search result.

Actually, there are 2 files containing "Floor" in both filename and content

This create a problem. When I search files in folders, the search result does not show all matched files.

Please advise how to resolve this. Thanks!