Adding Digital Signature field turns into a text field

Hi, I'm at my wits end with Adobe Acrobat Pro 2023.
I am trying to add digital signature fields to a form, like I've done a million times before on old versions, but it now appears as a text box even when the properties say it is a signature.
I saw a solution to this was to revert to the old UI, which I have done, untick 'this document requires signatures' and find a 'more' button but I don't have that?

Screenshot 1: My screen when opening the PDF

Screenshot 2: Yellow highlight under the signature field tool used, and the resulting fields
Screenshot 3: The preview of the field being text. This is how it is when saved as well. 

Please help!