Duplex Printer Problem

[Jonathan Ryshpan]

Whenever I try to print from Okular, a box with this message appears:
   There are conflicts in duplex settings. Do you want to fix them?
And printing is in fact funky: the options for double sided printing:
   Okular->Print->Options
are strange. The option "Long Side Printing" is selected (though greyed
out); the option "Off" is selectable, but if selected, no other option
can be selected afterward. Firefox doesn't allow control of duplex
printing using its native print dialog, but duplex can be controlled
using the system dialog.

Does anyone know what's going on or how to fix it.

Printer:
   HP Color Laserjet M255dw

Cups Version:
   cups-2.4.2-4.fc36.x86_64

System Info:
   Operating System: Fedora Linux 36
   KDE Plasma Version: 5.25.4
   KDE Frameworks Version: 5.97.0
   Qt Version: 5.15.5
   Kernel Version: 5.19.4-200.fc36.x86_64 (64-bit)
   Graphics Platform: X11
   Processors: 8 × Intel® Core™ i7-4790K CPU @ 4.00GHz
   Memory: 15.5 GiB of RAM
   Graphics Processor: Mesa Intel® HD Graphics 4600
   Manufacturer: ASUS

-- 
Sincerely Jonathan Ryshpan <jonrysh(a)pacbell.net&gt;

 Three percent exceeds 2 percent by 50 percent, 
 not by 1 percent.
 --Edward Denison