Interactive Pdf challenges

I'm looking for some insight on interactive pdf text entry. I've created several in InDesign for work. Some users are able to download them, save to desktop, and enter text no problem. Other users, including other computers in my own household, are not able to do this w/o the text shrinking when they switch to another item on the document. Or, they are limited to one sentence of text entry. Any thoughts? See all attachements. Attachments include instructions to end-user on how to download and then type into the pdfs once saved to desktop.