When using Windows 10 the driver for the PL2303 inside the USB connection cable for the Zyx, the Zyx software cannot find the COM port. Windows itself might see it. Or it cannot start the device. In all cases the Zyx software cannot find your Zyx.
The tricky part is that with the default Windows driver it finds the PL2303 driver, but it cannot start it. Installing the PL2303 driver from Tarot itself does not help since it’s an older version of the driver. Windows thus defaults to the newer one. Thus you not only have to install the Tarot USB PL2303 driver, but also select it explicitely in the device manager.