Hello,

Actually, you have to add sub item for the menu item so that dropdown can be appeared. So, please once verify the issue by adding sub item.

If the sub item is already present in your site and the issue is still existing then please provide us with site URL so that we can help you.

Note: sub item is the menu item under primary menu item(let: Home) which is located by dragging the item under primary menu item as shown in screenshot below:

http://prntscr.com/q89hno

If you have any queries further, let us know.

Thank you.