Preview + Markup PDF on iPad - Without the owner password, you do not have permission to save this document.

When I go to type/fill/sign a PDF form via Preview + Markup on my iPad the document comes up with a box saying "Without the owner password, you do not have permission to save this document”. This is a form downloaded for USCIS.gov so I obviously don't have the owner password.

I can fill out and sign the form on my MacBook Pro using PDF preview without the same message coming up. I noticed this happened on another PDF form the other day (from a completely different company). It also happens on my iPhone too.

I have always been able to fill out and sign forms on my iPad without any problems. I'm using iPadOS 15.1. Anyone else experience this recently?