Submenu not showing in Safari (ipad)

hi all I have searched the forum for a solution but cant find one.

I have created a site with menus on and some of these menus have submenus.

These all work as they should on a PC browser but on an Ipad in safari the submenu items do not display.

If I tap the menu item that has a sub menu on it noting happens

All other menu items without submenus work fine and go to their respective pages as you would expect.

As I say it worsk find on a pc it is just in safari the sub menu items do not display.

any idea would be apresiated

thanks