Sub menus not appearing on Mega menu

Hello support,

Please login to the home page with the provided superadmin credentails. From the main menu click the Coaches Portal menu item. This will take you to the coaches page here: webcando.org/index.php/coaches where you will see the Css3 Mega Menu at the top of the page.
On this menu you will see a menu item named Football Coaches with several sub menu items which are configured. However, as you see when hovering on the Football Coaches menu item, the menu does not expand down to show the sub-menu items.

The site is running Joomla 4.3.3 with php 8.2.13 . The template is from Rockettheme and called Supra and is Gantry 5.

Please help to tell me how to configure so the sub menu items show in the mega menu.

This is urgent for me as I need to deploy this site very soon for my customer so would greatly appreciate your attention to this.

Thanks in advance.

Warm regards,
Tom

Thank you Jackie!

Can you please explain the fix in case I encounter it again when adding other menus

Best regards,
Tom