Hi,
I am afraid that you have a special type of PDF form called "dynamic XFA from". As far as I know, no iOS PDF viewer apps (including Acrobat Reader) support viewing or editing of dynamic XFA forms.
If you actually open a dynamic XFA form in Acrobat Reader on iPad/iPhone, you will see the following alert.

If you see a message such as "please wait for document load...", you must be using some other PDF viewer or preview feature, not Acrobat Reader. I'd guess that you opened the dynamic XFA form in Safari or the PDF preview in Mail.
Please open the dynamic XFA form in Acrobat Reader on a Windows or Mac computer. The desktop version of Acrobat Reader supports static and dynamic XFA forms.
Sorry for the inconvenience.