HP Officejet Pro K550 Duplex Printing Problem

I am using Snow Leopard.

After several years of successful duplex use, I now need to intervene manually before each print job in order to get duplex printing.

Each time, I need to go to Printer Setup, select driver, and check "HP Two-sided Printer Accessory (Duplexor)." In the course of printing, the check is deleted, so I need to repeat this intervention each time I priint.

Is there a solution?