I upgraded fdrom the Tascam US-800 to the US-1800. I uninstalled the US-800 driers, then installed the US-1800 . Cubase still seems to think there is a US-1800 attached and won’t recognize the US-1800 drivers additional i/o.
The windows (if that´s the used OS) audio settings are independent from the Cubase audio settings. Setting a dedicated sound device in window has no influence on Cubase´s sound device.