Can't create a signature block

When I try to create a signature block for someone else to sign in an adobe acrobat document, the app defaults to the old format, in which you pasted the email address of the signatory, and then added emails for anyone cc'ed on the email, rather than the newer format, in which you paste only the email of the person signing it, then show where to sign, then review the document, at which point you add anyone to be cc'ed. After I paste the email of the signatory, and click on "Specify where to sign", it takes me to the document, but I am unable to create a signature box. I've tried rebooting my laptop, closing and reopening the adobe app, and re-downloading the document in PDF format, but the problem persists. Is this happening to anyone else? Any advice?