I'm using Adobe Acrobat Reader DC Version 2021.001.20150. I think you introduced a bug in the latest version, because I can no longer find a way to print double-sided. I'm using an HP Envy 4500 printer, which certainly does support double-sided printing, and I've used Acrobat Reader for years, but lately I can no longer print double-sided. When I press Properties in the print dialog box, that choice no longer appears.