iPad main menu requires two clicks, Android does not

Please view this website on an iPad (not a browser simulator).

iPad users are reporting that, for a main menu item with sub-pages, when the main item is clicked e.g. What’s On, the sub-menu block displays and remains on screen – as shown in this image – but the page (e.g. What’s On) remains ‘as was’ and “What’s On” is never shown.

The user must click for a second time on the main menu item for that page to be displayed.
(I don’t have an iPad so cannot verify this myself but the iPad behaviour has been reported to me by various users).

Now, you might reply that this is something to do with the lack of hover on a tablet because we are still in normal menu mode, and not mobile.

However, I have tried this on an Android tablet of similar screen size to an iPad and it works differently with the normal menu working correctly, namely…

1. Click once on What’s On
2. Sub-menu block is displayed for about 2 seconds
3. Sub-menu disappears
4. The page changes to the What’s On page

Why is the iPad behaviour different to Android? And more to the point, how can I get the iPad to work in the same way as Android (which is what the client wants)?