Hello,
If you want to keep the sub menu on the desktop, in this case you need to create a separate menu for mobile and desktop.
In your WordPress dashboard, go to Appearance > Menus.
Create a new menu and add the menu items that you want to display on mobile devices.
Go to Woodmart Header builder > edit current Header > Within the header builder, there should be an option to switch between desktop and mobile views. Switch to the mobile view.
Configure the mobile menu element you added to use the newly created mobile menu. This way, the content you’ve set up in the new mobile menu will be displayed in the mobile header. You can display a separate menu for mobile and desktop.
Best Regards.