Duplex Printing section of the Print Options - not applying one side only setting?

The Print on menu in the Duplex Printing section of the Print Options panel contains the following options:

One side only

Prints on one side of each sheet of paper. (Not working… is printing on both sides on my LaserJet)

Any ideas?
Right now my workaround is Acrobat PDF for final printouts.
Thank you,

Gregg Mazel
Dorico 6

If you’re on Mac, I think there are some posts in the forum specifically regarding duplex printing on that OS.

If you’re on Windows, I had a similar issue with my LaserJet which I resolved by trying different versions of the driver.