My PDF with form fields comes back blank after someone fills out and sends back

I created a new home questionnaire with form fields for the owners to fill out and send back to us.

It was working but we were testing it and if someone opens it and fills it out, then sends it back, when we open it, it's blank.

I also noticed this lock icon when I right click on the file and choose Get Info (Using a Mac)

I'm trying to figure out what could be the issue and we just want it to be able to send to the owners, have them fill it out, and then send back to us. We don't want to have all these extra steps they need to take.