Our Support team is ready to present a new tutorial that will show you how to fix the missing submenus issue in WordPress.
In order to fix the issue, you will need to update the jQuery library to at least 1.7.x. version.
Please download the file here.
Navigate to wp-content/themes/themeXXXX/js/directory on your server.
Find the current jQuery library file. Replace the current file with the downloaded one by renaming the jquery-1.7.2.min.js file.
Check your site, the issue should be fixed.
Feel free to check the detailed video tutorial below: