Drop down menu disappears in tablets

When I try to click on a drop down menu item in iPad, the menu disappears. I think the issue was addressed here: Dropdown menu not working on touch devices · Issue #9484 · foundation/foundation-sites · GitHub

They said this would be fixed with version 6.3.1, but the site I am working on uses version 6.6.3, and this issue is still happening. Also, none of those fixes suggested in the thread are working for me. Any insights? Anyone?