ImageClass MF656Cdw Not copying single-to-two sided

[Painter-Carver]

I have an ImageClass MF656Cdw color laser printer which will not print from one-sided to two-sided. Note that it has worked in the past but does not work now. Note further, that it will print from two-sided to two-sided but not from one-sided to two-sided. 

The SN is [hidden for privacy]

Thanks, in advance, for your assistance.

[mreg]

You don't provide nearly enough information for someone to venture a guess.  Are you printing from the LCD panel, or a computer?  If a computer what's the OS, the version, and the software you're using for printing.

[Painter-Carver]

I am using it as a stand alone copying machine - it is connected to my computer (PC with Windows 11) but I am performing all of the functions from the LCD panel. First selecting Copy, then two-sided, then number of copies (2 or greater) then B&W print.