Recent security updates to Windows 11 prevent the ION cash drawer driver from directly accessing the chipset information for the virtual serial adapter. This is indicated by the description for the virtual com port in Windows Device Manager to show the following message for the device: "PL2303TA DO NOT SUPPORT WINDOWS 11 OR LATER, PLEASE CONTACT YOUR SUPPLIER."
Fortunately, the installed driver also includes an older version of the driver that CAN be used with Windows 11. Start Windows device manager by clicking on the Windows start menu, and typing in "Device Manager". Click on the Device manager app when it is displayed, navigate to the Ports entry and expand it. Follow the instructions in the images below to enable the driver in Windows 11: