How can I combine two sheets into a report?

I created a report and chose 2 sheets as my source. The columns from one of the sheets are not showing any value. I checked that value in "Primary" columns of both sheet are identical. May I know if I have missed anything? Thank you for your guidance!

Some notes about the screenshot of my report below.

Column "Management Flag" and "Remark" are from one sheet, and they are displaying values correctly. Whereas the last column in the below screenshot/report, "Project Objective" comes from another sheet. And the entire column is empty.