Submenu Not Working On iPads With Revolution Sliders
If your submenus disappear when you try to use them on an iPad or other tablet device, it is due to a conflict with the Slider Revolution plugin. You can fix this by setting a global option for the Slider Revolution.
Step 1 - Click on the global settings button on the main rev slider page.
Step 2 - Scroll to the bottom of the options popup window and set "Use own hammer.js" file to off and click "update".
Step 3 - Clear your cache on your device and empty any cache from your plugins if you have any.