Thank you Hector. I can confirm that 2-sided printing works now on macOS Monterey 12.1, and with the latest driver on the support page (v101910-02). When printing pdfs from the Preview application, 2-sided printing can be chosen from the "Finishing" ...
I have the same problem, and installing the latest (v10.19.8) drivers for macOS11.3 doesn't work. When using the printer with canon drivers, duplex printing is not an option. Switching to Airprint is also usless since even though duplex printing work...