Hello Jonathanl,
We're sorry for the trouble you had with Adobe Reader, the duplex printing (double-sided) is a printer feature and if your printer has this property, you will be able to print double-sided through Adobe Reader.
Please go to the Advanced properties of the Printer and enable the Double-Sided printing. Make sure that you have the latest version of the Printer firmware/driver installed.
What is the make and model of the printer you have?
What is the dot version of Adobe Reader installed? To identify, refer to Identify the product and its version for Acrobat and Reader DC
You can Print double-sided using a single-sided printer, for detailed information, refer to Print double-sided | Adobe Acrobat, Reader DC
Let us know how it goes and share your observation.
Thanks,
Anand Sri.