We are sorry for the trouble. As described, Acrobat Reader DC prints small as if 4-up.
Is this a behavior with a particukar PDF file or with all the PDFs? Please try with a different PDF file and check.
What is the version of the Adobe Acrobat Reader DC you are using? To check the version got to Help > About Adobe Acrobat Reader and make sure that you have the latest version 20.12.20041 installed. Go to Help > Check for Updates.
Also, please check for any missing/pending update for prnter driver and firmware and try updating them and see if that makes any difference.
You may also try to print the PDF as image. Go to Print > Advanced > Print as Image and see if that helps.