Signing, [...] only works in Acrobat and nothing else.
Someone already mentioned it, but PDFGear is an excellent (and free) alternative to Acrobat.Is there an alternative to Acrobat that doesn't cost a fortune every year ?
And one can use Adobe Reader (free) for this. And a nice to have (free version) if Preview is having problems with a specific PDF file.
Are you not able to use Preview to sign an acrobat document?'adobe reader' used to be precisely what's required, until it was discontinued to force you onto the bloatware that is now called 'acrobat reader'. I still have the former on my comatose high sierra mac, which I have to wheel out each time I need to sign something.