Query concerning empty WP database on a subdomain

I have created a subdomain on my main hosting site and successfully installed WP on it. Plan to transfer the site using the Duplicator plugin to the main site, which is NOT a WP site, There is a factor that I believe needs to be solved before making the migration.

1: cPanel> File Manager contains the sub domain folders:
wp.mainsite.com
/cgi-bin
/wp
2: cPanel> File Manager root:home/mainsite
3: php MyAdmin
+ mainsite_wp10 (contains all of the files of the mainsite)
+ mainsite_wpx ( WP database is empty, this is the subdomain where WP has been installed )
4: MySQL Database
database: mainsite_wp10 size: 1.54 MB (main site)
database: mainsite_wpx size: 0.00 MB (subdomain with WP installed)

Both sites have users correctly added with full privileges. The WP site has been completed and visible when the URL is loaded to a browser.

So my question is: why do I have an empty database in my WP installation and how can I solve it? TIA

 

Thank you for your reply. Yes it is empty. When the database is viewed in phpMyAdmin >> No tables found in database.
This is the database I created with full user privileges and corresponds to the subdomain that I created on the localhost. When in the installation of WP is viewed in cPanel/FileManager all the contents of the installed site are visible.

 

Attaching a screen shot.

 

Thanks