HP Color Laserjet M651 always prints duplex

[rheckber]

I have an HP Color LaserJet M651 that no matter what I do always prints duplex.  We are using this to print via Pharos (Pay-for-Print).  I've selected single-sided in the driver and in the preferences and Pharos reports it printed single-sided but the document aways comes out duplex.  I've gone through the Embedded Web Server and even went through all settings in HPWebJetAdmin but I can't fin d a setting that defaults the printer to duplex.  

Looking at this document HP Color LaserJet Enterprise - Duplex turned ON by default in EU printers I'm led to believe there is a setting somewhere in the printer that will turn off duplex.  

Printer is running Firmware 2308995_579083.

I upgraded the Firmware to 241117_063723 (the latest) and I did see a setting for single sided 

and I selected that but I'm still getting duplex output.  

Any thoughts or ideas would be most welcome

[Valsimot]

Try to set it to Not installed it in Device Settings:

[rheckber · Accepted solution]

Turns out it appears to be a fault in the HP Color Laserjet M751 driver we were using.  No matter what setting we tried it printed duplex.  Switched to Generic HP PCL5 driver and worked perfect.