Dear Karen,
We don’t have any issues regarding the plugins sub menu and the update section inside the admin panel in the latest version of our theme. Please update your theme to the latest version if you have the older one.
Note: Make sure you do a back up of the current theme files and databases. https://www.styledthemes.com/installing-updating-themes/
Please provide your site url/login-details if it doesnot work.
Regards,
Sushil