I have the same issue, but in my case I have created new forms using Illustrator, and then edited them on Adobe LiveCycle so that when I open up the form, there are tick boxes, drop down boxes, etc.
However, when I open them on Adobe Acrobat on my iPad, these boxes,etc. do not appear.
Do you know the reason for this?
The Acrobat Reader mobile apps (for iOS, Android, and Windows Phone) do not support the PDF forms (static and dynamic XFA forms) that are created/edited with Adobe LiveCycle Designer.
I'd recommend using Acrobat Pro (desktop app) to add/edit form fields.
Please take a look at the AcroForms and XFA forms sections of the following document.
Sorry for the inconvenience.